ALLIANCE RESOURCE PARTNERS LP 10-K

Table of Contents ​ UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31 , 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM _____________TO_____________ COMMISSION FILE NO.: 0-26823 ALLIANCE RESOURCE PARTNERS, L.P . (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER) ​ ​ Delaware 73-1564280 (State or Other Jurisdiction of (IRS Employer Identification No.) Incorporation or Organization) ​ 1717 South Boulder Avenue, Suite 400 , Tulsa , Oklahoma 74119 (Address of Principal Executive Offices and Zip Code) ( 918 ) 295-7600 (Registrant's Telephone Number, Including Area Code) Securities registered pursuant to Section 12(b) of the Act: ​ ​ ​ ​ ​ Title of Each Class Trading Symbol Name of Each Exchange On Which Registered Common Units representing limited partner interests ​ ARLP ​ The NASDAQ Stock Market LLC Securities registered pursuant to Section 12(g) of the Act: None Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. ☒ Yes ☐ No Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. ☐ Yes ☒ No Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. ☒ Yes ☐ No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). ☒ Yes ☐ No Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ☒ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act. ​ ​ ​ ​ Large Accelerated Filer ☒ Accelerated Filer ☐ Non-Accelerated Filer ☐ Smaller Reporting Company ☐ ​ ​ (Do not check if smaller reporting company) Emerging Growth Company ☐ ​ ​ ​ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 726(b)) by the registered public accounting firm that prepared or issued its audit report. ☒ If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐ Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). ☐ Yes ☒ No The aggregate value of the common units held by non-affiliates of the registrant (treating all executive officers and directors of the registrant, for this purpose, as if they may be affiliates of the registrant) was approximately $ 1,948,772,132 as of June 30, 2023, the last business day of the registrant's most recently completed second fiscal quarter, based on the reported closing price of the common units as reported on The NASDAQ Stock Market LLC on such date. As of February 23, 2024, 128,061,981 common units were outstanding. DOCUMENTS INCORPORATED BY REFERENCE: None ​ ​ ​ Table of Contents TABLE OF CONTENTS ​ ​ ​ Page ​ ​ PART I ​ ​ Item 1. ​ Business ​ 1 Item 1A. ​ Risk Factors ​ 28 Item 1B. ​ Unresolved Staff Comments ​ 57 Item 1C. ​ Cybersecurity ​ 57 Item 2. ​ Properties ​ 60 Item 3. ​ Legal Proceedings ​ 77 Item 4. ​ Mine Safety Disclosures ​ 78 ​ ​ PART II ​ ​ Item 5. ​ Market for Registrant's Common Equity, Related Unitholder Matters and Issuer Purchases of Equity Securities ​ 79 Item 6. ​ [Reserved] ​ 80 Item 7. ​ Management's Discussion and Analysis of Financial Condition and Results of Operations ​ 80 Item 7A. ​ Quantitative and Qualitative Disclosures about Market Risk ​ 97 Item 8. ​ Financial Statements and Supplementary Data ​ 99 ​ ​ Report of Independent Registered Public Accounting Firm-Grant Thornton LLP (PCAOB ID Number 248) ​ 100 ​ ​ Consolidated Balance Sheets ​ 102 ​ ​ Consolidated Statements of Income ​ 103 ​ ​ Consolidated Statements of Comprehensive Income ​ 104 ​ ​ Consolidated Statements of Cash Flows ​ 105 ​ ​ Consolidated Statement of Partners' Capital ​ 106 ​ ​ Notes to Consolidated Financial Statements ​ 107 ​ ​ 1. Organization and Presentation ​ 107 ​ ​ 2. Summary of Significant Accounting Policies ​ 109 ​ ​ 3. Acquisitions ​ 117 ​ ​ 4. Inventories ​ 120 ​ ​ 5. Property, Plant and Equipment ​ 121 ​ ​ 6. Long-Term Debt ​ 122 ​ ​ 7. Income Taxes ​ 124 ​ ​ 8. Leases ​ 126 ​ ​ 9. Fair Value Measurements ​ 127 ​ ​ 10. Partners' Capital ​ 127 ​ ​ 11. Variable Interest Entities ​ 128 ​ ​ 12. E quity Investments ​ 130 ​ ​ 13. Revenue From Contracts With Customers ​ 131 ​ ​ 14. Earnings Per Limited Partner Unit ​ 132 ​ ​ 15. Employee Benefit Plans ​ 133 ​ ​ 16. Common Unit-Based Compensation Plans ​ 137 ​ ​ 17. Supplemental Cash Flow Information ​ 138 ​ ​ 18. Asset Retirement Obligations ​ 139 ​ ​ 19. Accrued Workers' Compensation and Pneumoconiosis Benefits ​ 140 ​ ​ 20. Related-Party Transactions ​ 142 ​ ​ 21. Commitments and Contingencies ​ 144 ​ ​ 22. Concentration of Credit Risk and Major Customers ​ 144 ​ ​ 23. Segment Information ​ 145 ​ ​ Supplemental Oil & Gas Reserve Information (Unaudited) ​ 148 ​ ​ Schedule I – Condensed Financial Information of Registrant ​ 153 Item 9. ​ Changes in and Disagreements with Accountant on Accounting and Financial Disclosure ​ 155 Item 9A. ​ Controls and Procedures ​ 155 Item 9B. ​ Other Information ​ 158 ​ ​ PART III ​ ​ Item 10. ​ Directors, Executive Officers and Corporate Governance of the General Partner ​ 159 Item 11. ​ Executive Compensation ​ 164 Item 12. ​ Security Ownership of Certain Beneficial Owners and Management and Related Unitholder Matters ​ 182 Item 13. ​ Certain Relationships and Related Transactions, and Director Independence ​ 183 Item 14. ​ Principal Accountant Fees and Services ​ 184 ​ ​ PART IV ​ ​ Item 15. ​ Exhibits and Financial Statement Schedules ​ 185 ​ ​ ii Table of Contents ​ GLOSSARY ​ The following are abbreviations and definitions of certain terms used in this document, some of which are defined by authoritative sources and others reflect those we commonly use in the coal and oil & gas industries: ​ ​ ​ 2020 Grants Restricted units that were granted in 2020 ​ 2022 Registration Statement In February 2022, we filed with the SEC a universal shelf registration statement which allows us to issue from time to time an indeterminate amount of debt or equity securities. ​ A&D Acquisitions and Divestitures ​ ACE Rule The Affordable Clean Energy Rule ​ Acquisition Gain The $177.0 million non-cash acquisition gain recognized in 2019 related to the acquisition of the remaining interests in AllDale Minerals LP and AllDale Minerals II, LP ​ AGP Alliance GP, LLC ​ AHGP Our subsidiary, Alliance Holdings GP, L.P. ​ AllDale I Our subsidiary, AllDale Minerals, LP ​ AllDale I & II Collectively our subsidiaries, AllDale Minerals, LP and AllDale Minerals II, LP ​ AllDale II Our subsidiary, AllDale Minerals II, LP ​ AllDale III AllDale Minerals III, LP ​ Alliance Coal Alliance Coal, LLC, an indirect wholly owned subsidiary of ARLP ​ Alliance Design Our subsidiary, Alliance Design Group, LLC ​ Alliance Finance Our subsidiary, Alliance Resource Finance Corporation ​ Alliance Minerals Alliance Minerals, LLC, an indirect wholly owned subsidiary of ARLP ​ Alliance Properties Our subsidiary, Alliance Properties, LLC ​ Alliance Resource Properties ​ Alliance Resource Properties, LLC, an indirect wholly owned subsidiary of ARLP Alliance WOR Properties Our subsidiary, Alliance WOR Properties, LLC ​ Allocation Date That first day of each month in which we prorate our items of income, gain, loss and deduction between transferors and transferees of our units based upon the ownership of our units on that day ​ AR Midland Our subsidiary, AR Midland, LP ​ ARH Alliance Resource Holdings, Inc. ​ ARLP Alliance Resource Partners, L.P., individually as the parent company, and not on a consolidated basis ​ iii Table of Contents ARLP Partnership The business and operations of Alliance Resource Partners, L.P., the parent company, as well as its consolidated subsidiaries; references to "Partnership", "we", "us" or "our" also refer to the ARLP Partnership ​ AROP Funding Our subsidiary, AROP Funding, LLC ​ ASC Accounting Standards Codification ​ Ascend Ascend Elements, Inc. ​ ASI Our subsidiary, Alliance Service, Inc. ​ Assigned reserves Reserves that have been designated for mining by a specific operation ​ ASU Accounting Standards Update ​ ASU 2023-07 ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures ​ ASU 2023-09 ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures ​ Audit Committee The audit committee of the Board of Directors ​ Bankruptcy Code Title 11 of the United State Code ​ Basin A depression in the crust of the Earth, caused by plate tectonic activity and subsidence, in which sediments accumulate. If rich hydrocarbon source rocks occur in combination with appropriate depth and duration of burial, then a petroleum system can develop within the basin. Most basins contain some amount of shale, thus providing opportunities for shale oil & gas exploration and production. ​ Basis differential The difference between the spot price of a commodity and the sales price at the delivery point where the commodity is sold ​ Bbl Stock tank barrel, or 42 United States gallons liquid volume, used in reference to crude oil or other liquid hydrocarbons ​ Belvedere Belvedere Operating, LLC ​ Belvedere Acquisition On September 9, 2022, AR Midland acquired approximately 394 net oil & gas royalty acres in the Delaware Basin from Belvedere. ​ Belvedere Acquisition Date ​ September 9, 2022 Bituminous coal Coal used primarily to generate electricity and to make coke for the steel industry with a heat value ranging between 10,500 and 15,500 Btus per pound ​ BLBA Federal Black Lung Benefits Act ​ Bluegrass Minerals Bluegrass Minerals Management, LLC ​ Board of Directors The board of directors of our general partner ​ BOE Barrels of oil equivalent, with six Mcf of natural gas being equivalent to one Bbl of crude oil, condensate, or natural gas liquids ​ iv Table of Contents Boulders Boulders Royalty Corp. ​ Boulders Acquisition On October 13, 2021, AR Midland acquired approximately 1,480 oil & gas net royalty acres in the Delaware Basin from Boulders. ​ BSER Best System of Emission Reduction ​ Btu British thermal unit ​ CAA Federal Clean Air Act ​ CAIR Clean Air Mercury Rule ​ Cavalier Minerals Our subsidiary, Cavalier Minerals JV, LLC ​ CCB Coal combustion by-products ​ CCRs Coal combustion residues ​ CEO Chief Executive Officer ​ CERCLA Federal Comprehensive Environmental Response, Compensation and Liability Act ​ CEQ Council on Environmental Quality ​ CFO Chief Financial Officer ​ CGA Cawley, Gillespie & Associates, Inc. ​ Circuit Court United States Court of Appeals for the District of Columbia ​ CODM Chief operating decision maker ​ Compensation Committee The compensation committee of the Board of Directors ​ Compliance coal Coal which, when burned, emits 1.2 pounds or less of sulfur dioxide per MMBtus, requiring no blending or other sulfur dioxide reduction technologies in order to comply with the requirements of the Federal Clean Air Act ​ Conflicts Committee The conflicts committee of the Board of Directors ​ Continuous miner A machine used in underground mining to cut coal from the seam and load it onto conveyors or into shuttle cars in a continuous operation ​ COP26 26 th Conference of the Parties ​ COP27 27 th Conference of the Parties ​ COP28 28 th Conference of the Parties ​ Corps of Engineers United States Army Corps of Engineers ​ COSO Committee of Sponsoring Organizations of the Treadway Commission ​ CPP Clean Power Plan ​ Craft Foundations Collectively, the Joseph W. Craft III Foundation and the Kathleen S. Craft Foundation v Table of Contents ​ Credit Agreement The credit agreement entered into by Alliance Coal, as borrower, on January 13, 2023 ​ CSAPR Cross-State Air Pollution Rule ​ CSX CSX Transportation, Inc. ​ CTO Chief Technology Officer ​ CWA Federal Clean Water Act ​ DERs Distribution equivalent rights ​ Developed acreage Acreage allocated or assignable to productive wells ​ Directors’ Deferred Compensation Plan ​ Alliance Resource Management GP, L.P. Amended & Restated Deferred Compensation Plan for Directors DMP Division of Mine Permits ​ DOL U.S. Department of Labor ​ EGUs Electric generating units ​ ELG Effluent Limitations Guidelines and Standards ​ EPA United States Environmental Protection Agency ​ EPU Earnings per limited partner unit ​ ESA Endangered Species Act ​ EV Electric vehicle ​ Excel Excel Mining, LLC ​ Exchange Act Securities Exchange Act of 1934 ​ FASB Financial Accounting Standards Board ​ FIPs Federal Implementation Plans ​ FMSHA Federal Mine Health and Safety Act of 1977, as amended by the Federal Mine Improvement and New Emergency Response Act of 2006 ​ Francis Francis Renewable Energy, LLC ​ GAAP Generally Accepted Accounting Principles ​ GFANZ Glasgow Financial Alliance for Net Zero ​ GHG Greenhouse gas ​ Gibson Our subsidiary, Gibson County Coal, LLC ​ Gibson South Our subsidiary, Gibson County Coal (South), LLC ​ vi Table of Contents Grant Thornton Grant Thornton LLP ​ Gross Acres The total acres in a specified tract in which an owner has a real property interest. For example, an owner who has a 25 percent interest in 100 acres has an ownership interest in 100 gross acres. ​ Hamilton Our subsidiary, Hamilton County Coal, LLC ​ Haymaker Haymaker Minerals & Royalties II, LLC ​ High-sulfur coal Based on market expectations, our classification of coal with a sulfur content of greater than 3% ​ HLBV Hypothetical liquidation at book value ​ Indicated mineral resource (coal) That part of a mineral resource for which quantity and grade or quality are estimated on the basis of adequate geological evidence and sampling. The level of geological certainty associated with an indicated mineral resource is sufficient to allow a qualified person to apply modifying factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. Because an indicated mineral resource has a lower level of confidence than the level of confidence of a measured mineral resource, an indicated mineral resource may only be converted to a probable mineral reserve. ​ Inferred mineral resource (coal) That part of a mineral resource for which quantity and grade or quality are estimated on the basis of limited geological evidence and sampling. The level of geological uncertainty associated with an inferred mineral resource is too high to apply relevant technical and economic factors likely to influence the prospects of economic extraction in a manner useful for evaluation of economic viability. Because an inferred mineral resource has the lowest level of geological confidence of all mineral resources, which prevents the application of the modifying factors in a manner useful for evaluation of economic viability, an inferred mineral resource may not be considered when assessing the economic viability of a mining project, and may not be converted to a mineral reserve. ​ Infinitum Infinitum Electric, Inc. ​ Intermediate Partnership Alliance Resource Operating Partners, L.P., the intermediate partnership of Alliance Resource Partners, L.P. ​ IRAs Individual retirement accounts ​ IRS Internal Revenue Service ​ Island Creek Island Creek Coal Company ​ Jase Jase Minerals, LP ​ Jase Acquisition On October 26, 2022, AR Midland acquired approximately 3,928 net oil & gas royalty acres in the Permian Basin from Jase. ​ Jase Acquisition Date October 26, 2022 ​ JC Land JC Land LLC ​ JC Resources JC Resources LP ​ JC Resources Acquisition On February 22, 2023, we acquired approximately 2,682 oil & gas net royalty acres in the Delaware Basin from JC Resources LP. vii Table of Contents ​ KYDNR Kentucky Department of Natural Resources ​ Long-term contracts Contracts having a term of one year or greater ​ Longwall mining One of two major underground coal mining methods, utilizing specialized equipment to remove nearly all of a coal seam over a very large area. ​ Low-sulfur coal Based on market expectations, we classify coal with a sulfur content of less than 1.5% ​ LTIP Amended and Restated Alliance Coal, LLC 2000 Long-Term Incentive Plan ​ MAC Our subsidiary, Mid-America Carbonates, LLC ​ Matrix Design Our subsidiary, Matrix Design Group, LLC ​ Matrix Group Collectively our subsidiaries, Alliance Design, ASI and its subsidiary, Matrix Design and its subsidiaries Matrix Design International, LLC, Matrix Design Africa (PTY) LTD, and Matrix Design (Australia) PTY, LTD ​ MATS Mercury and Air Toxics Standards ​ MBbls Thousand barrels of crude oil or other liquid hydrocarbons ​ MBOE One thousand barrels of crude oil equivalent, determined using a ratio of six Mcf of natural gas to one Bbl of crude oil, condensate, or natural gas liquids ​ MC Mining Our subsidiary, MC Mining, LLC ​ Mcf Thousand cubic feet of natural gas ​ Measured mineral resource (coal) That part of a mineral resource for which quantity and grade or quality are estimated on the basis of conclusive geological evidence and sampling. The level of geological certainty associated with a measured mineral resource is sufficient to allow a qualified person to apply modifying factors, as defined in this section, in sufficient detail to support detailed mine planning and final evaluation of the economic viability of the deposit. Because a measured mineral resource has a higher level of confidence than the level of confidence of either an indicated mineral resource or an inferred mineral resource, a measured mineral resource may be converted to a proven mineral reserve or to a probable mineral reserve. ​ Medium-sulfur coal Based on market expectations, our classification of coal with a sulfur content of 1.5% to 3% ​ Metallurgical coal Coal primarily used in the production of steel ​ Mettiki Mettiki Complex, including the Mountain View mine operated by our subsidiary, Mettiki (WV) and the preparation plant operated by our subsidiary, Mettiki (MD) ​ Mettiki (MD) Our subsidiary, Mettiki Coal, LLC ​ Mettiki (WV) Our subsidiary, Mettiki Coal (WV), LLC ​ MGP Alliance Resource Management GP, L.P., ARLP’s general partner ​ MINER Act Federal Mine Improvement and New Emergency Response Act of 2006 ​ viii Table of Contents Mineral Interest Mineral interests are real-property interests that are typically perpetual and grant ownership to the oil & gas under a tract of land or the rights to explore for, develop, and produce oil & gas on that land or to lease those exploration and development rights to a third party ​ Mineral reserve (coal) An estimate of tonnage and grade or quality of indicated and measured mineral resources that, in the opinion of the qualified person, can be the basis of an economically viable project. More specifically, it is the economically mineable part of a measured or indicated mineral resource, which includes diluting materials and allowances for losses that may occur when the material is mined or extracted. ​ Mineral resource (coal) A concentration or occurrence of material of economic interest in or on the Earth's crust in such form, grade or quality, and quantity that there are reasonable prospects for economic extraction. A mineral resource is a reasonable estimate of mineralization, taking into account relevant factors such as cut-off grade, likely mining dimensions, location or continuity that, with the assumed and justifiable technical and economic conditions, is likely to, in whole or in part, become economically extractable. It is not merely an inventory of all mineralization drilled or sampled. ​ MMBtus Million British thermal units ​ MMcf Million cubic feet of natural gas ​ Mr. Craft Joseph W. Craft III, the Chairman, President and Chief Executive Officer of MGP ​ MSHA Mine Safety and Health Administration ​ Mt. Vernon Our subsidiary, Mt. Vernon Transfer Terminal, LLC ​ NAAQS National Ambient Air Quality Standards ​ Named Executive Officers Our Chairman, President and CEO (our principal executive officer), the Senior Vice President and Chief Financial Officer (our principal financial officer) and the three most highly compensated executive officers in 2023 ​ NEPA National Environmental Policy Act ​ Net acres The actual ownership interest within a specified tract expressed in acres. For example, an owner who has a 50 percent interest in 100 acres owns 50 net acres. ​ Net royalty acres Mineral ownership standardized to a 12.5%, or 1/8 th , royalty interest ​ NGFS Network for Greening the Financial System ​ NGLs Natural gas liquids are components of natural gas that are liquid at the surface in field facilities or gas-processing plants. Natural gas liquids can be classified according to their vapor pressures as low (condensate), intermediate (natural gasoline), and high (liquefied petroleum gas) vapor pressure. Natural gas liquids include propane, butane, pentane, hexane, and heptane, but not methane and ethane since these hydrocarbons need refrigeration to be liquefied. The term is commonly abbreviated as NGL. ​ NGP NGP Energy Capital Management, LLC ​ NGP ET IV NGP Energy Transition, L.P. ​ NS Norfolk Southern Railway Company ​ ix Table of Contents NSPS New Source Performance Standards ​ NSR New source review ​ Oil & gas Crude oil, natural gas, and natural gas liquids ​ Old Ben Old Ben Coal Company ​ Old Ben Leases Leases originally taken by AMAX Coal Company and Old Ben Coal Company in the mid to late 1970’s and early 1980’s ​ Operator The individual or company responsible for the exploration and/or production of a Mineral Interest which, with respect to our Mineral Interests, are unaffiliated third-parties ​ OSM ​ OWCP Federal Office of Surface Mining ​ Office of Workers’ Compensation Programs ​ PADEP Pennsylvania Department of Environmental Protection ​ PAL Paducah & Louisville Railway, Inc. ​ Patriot Patriot Coal Corporation ​ PCAOB Public Company Accounting Oversight Board ​ Peabody Peabody Energy Corporation ​ Pension Plan Alliance Coal, LLC and Affiliates Pension Plan for Coal Employees ​ PM Fine particulate matter ​ Preparation plant A facility used for crushing, sizing, and washing coal to remove impurities and to prepare it for use by a particular customer ​ Probable mineral reserve (coal) The economically mineable part of an indicated and, in some cases, a measured mineral resource ​ Productive well A well that is found to be capable of producing hydrocarbons in sufficient quantities such that proceeds from the sale of the production exceed production expenses and taxes ​ Proved developed reserves (oil & gas) Proved reserves that can be expected to be recovered through existing wells with existing equipment and operating methods ​ Proved reserves or properties (oil & gas) Proved reserves are those quantities of oil & gas which, by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be economically producible—from a given date forward, from known reservoirs, and under existing economic conditions, operating methods, and government regulations—prior to the time at which contracts providing the right to operate expire, unless evidence indicates that renewal is reasonably certain, regardless of whether deterministic or probabilistic methods are used for the estimation. The project to extract the hydrocarbons must have commenced or the operator must be reasonably certain that it will commence the project within a reasonable time. ​ Proved undeveloped reserves (oil & gas) Proved reserves that are expected to be recovered from new wells on undrilled acreage or from existing wells where a relatively major expenditure is required for recompletion ​ x Table of Contents Proven mineral reserve (coal) The economically mineable part of a measured mineral resource and can only result from conversion of a measured mineral resource ​ PSSP Profit sharing and savings plan ​ PUDs Proved undeveloped reserves ​ RCRA Federal Resource Conservation and Recovery Act ​ Reclamation The restoration of land and environmental standards to a mining site after the coal is extracted, including returning the land to its approximate original appearance, restoring topsoil, and planting native grass and ground covers ​ Reserves (oil & gas) Reserves are estimated remaining quantities of oil and natural gas and related substances anticipated to be economically producible, as of a given date, by application of development projects to known accumulations. In addition, there must exist, or there must be a reasonable expectation that there will exist, the legal right to produce or a revenue interest in the production, installed means of delivering oil and natural gas or related substances to the market, and all permits and financing required to implement the project. Reserves should not be assigned to adjacent reservoirs isolated by major, potentially sealing, faults until those reservoirs are penetrated and evaluated as economically producible. ​ RESPEC RESPEC Company, LLC ​ Revolving Credit Facility The Credit Agreement provides for a $425 million revolving credit facility, which includes a sublimit of $15.0 million for swingline borrowings and permits the issuance of letters of credit up to the full amount of $425 million ​ RGGI Regional Greenhouse Gas Initiative agreement ​ River View Our subsidiary, River View Coal, LLC ​ Room-and-pillar mining One of two major underground coal mining methods, utilizing continuous miners creating a network of "rooms" within a coal seam, leaving behind "pillars" of coal used to support the roof of a mine ​ Royalty interest An interest that gives the owner the right to receive a portion of the resources or revenues without having to carry any costs of development or operations ​ Sebree Our subsidiary, Sebree Mining, LLC ​ SEC United States Securities and Exchange Commission ​ Securities Act Securities Act of 1933 ​ Securitization Facility Certain direct and indirect wholly owned subsidiaries of our Intermediate Partnership are party to a $90.0 million accounts receivable securitization facility. ​ Senior Notes An aggregate original principal amount of $400.0 million of senior unsecured notes due 2025 issued on April 24, 2017 by the Intermediate Partnership and Alliance Finance. ​ SERP Alliance Coal, LLC Supplemental Executive Retirement Plan ​ SIPs State implementation plans ​ Skyland Skyland Minerals, L.P. xi Table of Contents ​ Skyland Acquisition On December 7, 2023, we acquired approximately 2,372 oil & gas net royalty acres predominantly in the Anadarko Basin, along with acreage in the Williston and Delaware Basins from Skyland Minerals, L.P. and Haymaker Minerals & Royalties II, LLC. ​ Skyland Acquisition Date December 7, 2023 ​ SMCRA Federal Surface Mining Control and Reclamation Act of 1977 ​ STIP Alliance Resource Management GP, LLC Short-Term Incentive Plan ​ Subsidiary Guarantors Certain subsidiaries of ARLP, including the Intermediate Partnership and most of the direct and indirect subsidiaries of Alliance Coal, guaranteeing the Credit Agreement. ​ Tax Election On March 15, 2022, Alliance Minerals changed its federal income tax status from a pass-through entity to a taxable entity via a "check the box" election. ​ Term Loan The Credit Agreement provides for a term loan in an aggregate principal amount of $75 million. ​ Thermal coal Coal used primarily in the generation of electricity ​ TMDL Total Maximum Daily Load ​ TRRC Texas Railroad Commission ​ TRS Technical Report Summary ​ Tunnel Ridge Our subsidiary, Tunnel Ridge, LLC ​ UIC Underground Injection Control ​ Unassigned reserves (coal) ​ Reserves that have not yet been designated for mining by a specific operation Undeveloped acreage (oil & gas) Acreage on which wells have not been drilled or completed to a point that would permit the production of commercial quantities of oil & gas regardless of whether such acreage contains proved reserves ​ Unproved reserves or properties (oil & gas) Properties with no proved reserves. We also consider unproved reserves or properties to be defined as the estimated quantities of oil & gas determined based on geological and engineering data similar to that used in estimates of proved reserves; but technical, contractual, economic, or regulatory uncertainties preclude such reserves from being classified as proved. ​ USEA United States Energy Association ​ USFWS United States Fish and Wildlife Service ​ USGA United States Geological Survey ​ Valley Camp Valley Camp Coal Company ​ VIE Variable interest entity ​ VOC Volatile organic compound ​ Warrior Our subsidiary, Warrior Coal, LLC xii Table of Contents ​ Webster Our subsidiary, Webster County Coal, LLC ​ Wildcat Insurance Our subsidiary, Wildcat Insurance, LLC ​ WKY CoalPlay WKY CoalPlay, LLC ​ WKY11 West Kentucky No. 11 ​ WKY6 West Kentucky No. 6 ​ WKY7 West Kentucky No. 7 ​ WKY9 West Kentucky No. 9 ​ WOTUS Waters of the United States ​ WVDEP West Virginia Department of Environmental Protection ​ ​ ​ ​ ​ xiii Table of Contents FORWARD-LOOKING STATEMENTS ​ Certain statements and information in this Annual Report on Form 10-K, and certain oral statements made from time to time by our representatives, constitute "forward-looking statements." These statements are based on our beliefs as well as assumptions made by, and information currently available to, us. When used in this document, the words "anticipate," "believe," "continue," "could," "estimate," "expect," "forecast," "foresee," "may," "outlook," "plan," "project," "potential," "should," "will," "would," and similar expressions identify forward-looking statements. Without limiting the foregoing, all statements relating to our future outlook, anticipated capital expenditures, future cash flows and borrowings, and sources of funding are forward-looking statements. These forward-looking statements are based on our current expectations and beliefs concerning future developments and reflect our current views with respect to future events and are subject to numerous assumptions that we believe are reasonable, but are open to a wide range of uncertainties and business risks, and actual results could differ materially from those discussed in these statements. Among the factors that could cause actual results to differ from those in the forward-looking statements are: ​ ● decline in the coal industry's share of electricity generation, including as a result of environmental concerns related to coal mining and combustion, the cost and perceived benefits of other sources of electricity and fuels, such as oil & gas, nuclear energy, and renewable fuels and the planned retirement of coal-fired power plants in the U.S.; ● changes in macroeconomic and market conditions and market volatility, and the impact of such changes and volatility on our financial position; ● changes in global economic and geo-political conditions or changes in industries in which our customers operate; ● changes in commodity prices, demand and availability which could affect our operating results and cash flows; ● the outcome or escalation of current hostilities in Ukraine and the Israel-Gaza conflict; ● the severity, magnitude, and duration of any future pandemics and impacts of such pandemics and of businesses' and governments' responses to such pandemics on our operations and personnel, and on demand for coal, oil, and natural gas, the financial condition of our customers and suppliers and Operators, available liquidity and capital sources and broader economic disruptions; ● actions of the major oil-producing countries with respect to oil production volumes and prices could have direct and indirect impacts over the near and long term on oil & gas exploration and production operations at the properties in which we hold mineral interests; ● changes in competition in domestic and international coal markets and our ability to respond to such changes; ● potential shut-ins of production by the Operators of the properties in which we hold oil & gas mineral interests due to low commodity prices or the lack of downstream demand or storage capacity; ● risks associated with the expansion of our operations and properties; ● our ability to identify and complete acquisitions and to successfully integrate such acquisitions into our business and achieve the anticipated benefits therefrom; ● our ability to identify and invest in new energy and infrastructure transition ventures; ● the success of our development plans for Matrix Group, and our investments in emerging infrastructure and technology companies; ● dependence on significant customer contracts, including renewing existing contracts upon expiration; ● adjustments made in price, volume, or terms to existing coal supply agreements; ● the effects of and changes in trade, monetary and fiscal policies and laws central bank policy actions including interest rates, bank failures, and associated liquidity risks; ● the effects of and changes in taxes or tariffs and other trade measures adopted by the United States and foreign governments; ● legislation, regulations, and court decisions and interpretations thereof, both domestic and foreign, including those relating to the environment and the release of greenhouse gases, mining, miner health and safety, hydraulic fracturing, and health care; ● deregulation of the electric utility industry or the effects of any adverse change in the coal industry, electric utility industry, or general economic conditions; ● investors' and other stakeholders' increasing attention to environmental, social, and governance matters; ● liquidity constraints, including those resulting from any future unavailability of financing; ● customer bankruptcies, cancellations or breaches to existing contracts, or other failures to perform; ● customer delays, failure to take coal under contracts or defaults in making payments; xiv Table of Contents ● our productivity levels and margins earned on our coal sales; ● disruptions to oil & gas exploration and production operations at the properties in which we hold mineral interests; ● changes in equipment, raw material, service or labor costs or availability, including due to inflationary pressures; ● changes in our ability to recruit, hire and maintain labor; ● our ability to maintain satisfactory relations with our employees; ● increases in labor costs including costs of health insurance and taxes resulting from the Affordable Care Act, adverse changes in work rules, or cash payments or projections associated with workers' compensation claims; ● increases in transportation costs and risk of transportation delays or interruptions; ● operational interruptions due to geologic, permitting, labor, weather, supply chain shortage of equipment or mine supplies, or other factors; ● risks associated with major mine-related accidents, mine fires, mine floods, or other interruptions; ● results of litigation, including claims not yet asserted; ● foreign currency fluctuations that could adversely affect the competitiveness of our coal abroad; ● difficulty maintaining our surety bonds for mine reclamation as well as workers' compensation and black lung benefits; ● difficulty in making accurate assumptions and projections regarding post-mine reclamation as well as pension, black lung benefits, and other post-retirement benefit liabilities; ● uncertainties in estimating and replacing our coal mineral reserves and resources; ● uncertainties in estimating and replacing our oil & gas reserves; ● uncertainties in the amount of oil & gas production due to the level of drilling and completion activity by the operators of our oil & gas properties; ● uncertainties in the future of the electric vehicle industry and the market for EV charging stations; ● the impact of current and potential changes to federal or state tax rules and regulations, including a loss or reduction of benefits from certain tax deductions and credits; ● difficulty obtaining commercial property insurance, and risks associated with our participation in the commercial insurance property program; ● evolving cybersecurity risks, such as those involving unauthorized access, denial-of-service attacks, malicious software, data privacy breaches by employees, insiders or others with authorized access, cyber- or phishing attacks, ransomware, malware, social engineering, physical breaches, or other actions; ● difficulty in making accurate assumptions and projections regarding future revenues and costs associated with equity investments in companies we do not control; and ● other factors, including those discussed in "Item 1A. Risk Factors" and "Item 3. Legal Proceedings." ​ If one or more of these or other risks or uncertainties materialize, or should our underlying assumptions prove incorrect, our actual results could differ materially from those described in any forward-looking statement. When considering forward-looking statements, you should also keep in mind our risk factors and legal proceedings. Known material factors that could cause our actual results to differ from those in the forward-looking statements are described in "Item 1A. Risk Factors" and "Item 3. Legal Proceedings." We disclaim any obligation to update or revise any forward-looking statements or to announce publicly the result of any revisions to any of the forward-looking statements to reflect future events or developments unless required by law. ​ You should consider the information above when reading any forward-looking statements contained in this Annual Report on Form 10-K; other reports filed by us with the SEC; our press releases; our website www.arlp.com ; and written or oral statements made by us or any of our officers or other authorized persons acting on our behalf. ​ ​ xv Table of Contents ​ ​ PART I ​ ITEM 1. BUSINESS ​ Introduction ​ We are a diversified natural resource company that generates operating and royalty income from the production and marketing of coal to major domestic and international utilities and industrial users as well as royalty income from oil & gas mineral interests located in strategic producing regions across the United States. The primary focus of our business is to maximize the value of our existing mineral assets, both in the production of coal from our mining assets and the leasing and development of our coal and oil & gas mineral ownership. In addition, we are positioning ourselves as a reliable energy provider for the future as we pursue opportunities that support the advancement of energy and related infrastructure. We intend to pursue strategic investments that leverage our core competencies and relationships with electric utilities, industrial customers, and federal and state governments. We believe that our diverse and rich resource base and strategic investments will allow us to continue to create long-term value for unitholders. ​ We are the largest coal producer in the eastern United States with seven operating underground mining complexes in Illinois, Indiana, Kentucky, Maryland, Pennsylvania, and West Virginia as well as a coal-loading terminal in Indiana on the Ohio River. We manage and report our coal operations under two regions, Illinois Basin and Appalachia. We market our coal production to major domestic and international utilities and industrial users. ​ We own mineral and royalty interests in approximately 67,700 net royalty acres, including approximately 4,000 net royalty acres attributable to our equity interest in AllDale III, in premier oil & gas producing regions in the United States, primarily the Permian, Anadarko, and Williston Basins. While we own both oil & gas mineral and royalty interests, we refer to them collectively as mineral interests throughout our discussions of our business as the majority of our holdings are mineral interests. We market our oil & gas mineral interests for lease to Operators in those regions and generate royalty income from the leasing and development of those mineral interests. Reserve additions and the associated cash flows are expected to increase from the development of our existing mineral interests and through acquisitions of additional mineral interests. ​ We have approximately 663.2 million tons of coal mineral reserves and 1.06 billion tons of coal mineral resources in Illinois, Indiana, Kentucky, Maryland, Pennsylvania and West Virginia. Substantially, all of our coal mineral resources and 557.7 million tons of our coal mineral reserves are owned or leased by Alliance Resource Properties, which are (a) leased or subleased to internal mining complexes or (b) near other internal and external coal mining operations but not yet leased. We market our coal mineral reserves and resources to the coal mining operations that are able to access them and generate royalty income from the leasing and development of those coal mineral reserves and resources. ​ We have invested in energy and infrastructure opportunities including Ascend, Francis, Infinitum, and NGP ET IV as described below. ​ In addition, through our technology company, Matrix Group, we develop and market industrial, mining and technology products and services worldwide. ​ ARLP, a Delaware limited partnership, completed its initial public offering on August 19, 1999, and is listed on the NASDAQ Global Select Market under the ticker symbol "ARLP." We are managed by our sole general partner, MGP, a Delaware limited liability company, which holds a non-economic general partner interest in ARLP. ​ Oil & Gas Acquisitions ​ The following acquisitions enhance our ownership position in the Permian Basin and further our business strategy to grow our Oil & Gas Royalties segment. ​ 1 Table of Contents Acquisition Agreement ​ On January 27, 2023, we entered into a one-year collaborative agreement with a third party effective January 1, 2023, committing up to $35.0 million for the acquisition of oil & gas mineral interests in the Midland and Delaware basins. Under the agreement, the third party assisted us in the identification, evaluation, and acquisition of target oil & gas mineral interests. In exchange for these services, the third party received a participation share, partially funded by the third party, and was paid a periodic management fee. We acquired $13.2 million oil & gas mineral interests under the agreement in 2023. On February 19, 2024, we renewed this agreement for an additional one-year term, committing up to $25.0 million. ​ JC Resources ​ On February 22, 2023, we acquired approximately 2,682 oil & gas net royalty acres in the Delaware Basin from JC Resources, a related party entity owned by Mr. Craft, for $72.3 million. ​ Skyland ​ On December 7, 2023, we acquired approximately 2,372 oil & gas net royalty acres predominantly in the Anadarko Basin, along with acreage in the Williston and Delaware Basins from Skyland and Haymaker for a combined purchase price of $14.5 million. ​ Growth Investments and Opportunities ​ The following investments in the advancement of energy and related infrastructure further our business strategy to develop strategic relationships and invest in attractive opportunities that leverage our core competencies and build platforms for future lines of business with long-term growth and cash flow generation. For more information on our acquisitions and investments, please read "Item 8. Financial Statements and Supplementary Data—Note 3 – Acquisitions","—Note 11 – Variable Interest Entities" and "—Note 12 – Equity Investments" of this Annual Report on Form 10-K. ​ Francis ​ On April 5, 2022, we made a $20.0 million convertible note investment in Francis which converted to a preferred equity interest on April 1, 2023. Francis currently is active in the installation, management and operation of metered-for-fee, public-access EV charging stations. Francis also develops and constructs EV charging stations for third-party customers. ​ Ascend ​ On September 6, 2023, we purchased $25.0 million of Series D Preferred Stock in Ascend. Ascend is a U.S.-based manufacturer and recycler of sustainable, closed-loop engineered battery materials for electric vehicles. Ascend is currently constructing North America's first commercial-scale manufacturing facility located near Hopkinsville, Kentucky, that when complete, will produce enough cathode materials for 750,000 electric vehicles per year. ​ Infinitum ​ On September 8, 2023, we increased our investment in Infinitum to $66.6 million by purchasing $24.6 million of Series E Preferred Stock. Infinitum is a Texas-based startup developer and manufacturer of electric motors featuring printed circuit board stators which have the potential to result in motors that are smaller, lighter, quieter, more efficient and capable of operating at a fraction of the carbon footprint of conventional electric motors. ​ Matrix Group ​ Matrix Group provides a variety of technology products and services for our mining operations and certain industrial and mining technology products and services to third parties. On January 16, 2024, Matrix Design entered into an agreement with Infinitum to jointly develop and distribute high-efficiency motors and advanced motor controllers designed specifically for the mining industry. Under the agreement, Matrix Design will integrate Infinitum's motor technology into mining equipment of our operating subsidiaries to provide performance validation in production environments for jointly 2 Table of Contents developed products and to improve our operational efficiency, and market the jointly developed technology and products to third parties worldwide. ​ The following diagram depicts our simplified organization and ownership as of December 31, 2023: ​ ​ Our internet address is www.arlp.com , and we make available free of charge on our website our Annual Reports on Form 10-K, our Quarterly Reports on Form 10-Q, our Current Reports on Form 8-K, Forms 3, 4 and 5 for our Section 16 filers and other documents (and amendments and exhibits, such as press releases, to such filings) as soon as reasonably practicable after we electronically file with or furnish such material to the SEC. Information on our website or any other website is not incorporated by reference into this report and does not constitute a part of this report. ​ The SEC maintains a website that contains reports, proxy and information statements, and other information for issuers, including us. The public can obtain any documents that we file with the SEC at www.sec.gov . ​ Coal Mining Operations ​ Coal is used primarily for the generation of electric power and the production of steel but is also used for chemical, food, and cement processing. We produce bituminous coal from our underground mines that is sold to customers principally for electric power generation (thermal) and the production of steel (metallurgical). We have established long-term relationships with customers through exemplary and consistent performance. 3 Table of Contents ​ At December 31, 2023, our mining operations had access to approximately 663.2 million tons of coal mineral reserves and 1.06 billion tons of coal mineral resources in Illinois, Indiana, Kentucky, Maryland, Pennsylvania, and West Virginia. Substantially, all of our coal mineral resources and 557.7 million tons of our coal mineral reserves are owned or leased by Alliance Resource Properties and are currently leased or subleased or held for lease or sublease to our mining operations or others. We produce a diverse range of thermal and metallurgical coal with varying sulfur and heat contents, which enables us to satisfy the broad range of specifications required by our customers. In 2023, we sold 34.4 million tons of coal and produced 34.9 million tons. Of the 34.4 million tons sold, approximately 60% were leased from Alliance Resource Properties. The coal we sold in 2023 was approximately 3.6% low-sulfur coal, 33.4% medium-sulfur coal, and 63.0% high-sulfur coal. In 2023, approximately 80.9% of our tons sold were purchased by domestic electric utilities and 15.7% were sold into the international markets through brokered transactions. The balance of our tons sold was to third-party resellers and industrial consumers. For tons sold to domestic electric utilities, 100.0% were sold to utility plants with installed pollution control devices. The Btu content of our coal ranges from 11,450 to 13,200. ​ The following chart summarizes our coal production by region for the last three years. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Coal Regions 2023 2022 2021 ​ ​ (tons in millions) Illinois Basin 25.2 24.3 22.2 ​ Appalachia 9.7 11.2 10.0 ​ Total 34.9 35.5 32.2 ​ ​ ​ 4 Table of Contents The following map shows the location of our coal mining operations: ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Operations: ​ D. WARRIOR COMPLEX ​ G. METTIKI COMPLEX ​ A. GIBSON COMPLEX ​ Warrior Mine ​ Mountain View Mine ​ Gibson South Mine ​ Mining Type: Underground ​ Mining Type: Underground ​ Mining Type: Underground ​ Mining Access: Slope & Shaft ​ Mining Access: Slope & Shaft ​ ​ Mining Access: Slope & Shaft ​ Mining Method: Room & Pillar ​ Mining Method: Longwall ​ ​ Mining Method: Room & Pillar ​ Coal Type: Medium/High-Sulfur ​ & Continuous Miner ​ ​ Coal Type: Low/Medium-Sulfur ​ Transportation: Barge, Railroad, ​ Coal Type: Low/Medium ​ ​ Transportation: Barge, Railroad ​ & Truck ​ Sulfur - Metallurgical ​ ​ & Truck ​ ​ ​ Transportation: Railroad ​ ​ ​ ​ E. MOUNT VERNON ​ & Truck ​ ​ B. RIVER VIEW COMPLEX ​ TRANSFER TERMINAL ​ ​ ​ ​ a) River View Mine ​ Rail or Truck to Ohio River Barge ​ H. MC MINING COMPLEX ​ ​ b) Henderson County Mine ​ Transloading Facility ​ Excel Mine No. 5 ​ ​ Mining Type: Underground ​ ​ ​ Mining Type: Underground ​ ​ Mining Access: Slope & Shaft ​ Appalachian Operations: ​ Mining Access: Slope & Shaft ​ ​ Mining Method: Room & Pillar ​ F. TUNNEL RIDGE COMPLEX ​ Mining Method: Room & Pillar ​ ​ Coal Type: Medium/High-Sulfur ​ Tunnel Ridge Mine ​ Coal Type: Low-Sulfur ​ ​ Transportation: Barge & Truck ​ Mining Type: Underground ​ Transportation: Barge, Railroad, ​ ​ ​ ​ Mining Access: Slope & Shaft ​ & Truck ​ ​ C. HAMILTON COMPLEX ​ Mining Method: Longwall ​ ​ ​ ​ Hamilton Mine ​ & Continuous Miner ​ ​ ​ ​ Mining Type: Underground ​ Coal Type: Medium/High-Sulfur ​ ​ ​ ​ Mining Access: Slope & Shaft ​ Transportation: Barge ​ ​ ​ ​ Mining Method: Longwall ​ ​ ​ ​ ​ ​ & Continuous Miner ​ ​ ​ ​ ​ ​ Coal Type: Medium/High-Sulfur ​ ​ ​ ​ ​ ​ Transportation: Barge, Railroad ​ ​ ​ ​ ​ ​ & Truck ​ ​ ​ ​ ​ ​ 5 Table of Contents We lease most of our coal mineral reserves and resources from Alliance Resource Properties or private parties and generally have the right to maintain leases in force until the exhaustion of mineable and merchantable coal located within the leased premises or a larger coal mineral reserve or resource area. These leases provide for royalties to be paid to the lessors at a fixed amount per ton or as a percentage of the sales price. Many leases require payment of minimum royalties, payable either at the time of the execution of the lease or in periodic installments, even if no mining activities have begun. These minimum royalties are normally credited against the production royalties owed to a lessor once coal production has commenced. ​ Illinois Basin Operations ​ Our Illinois Basin mining operations are located in western Kentucky, southern Illinois, and southern Indiana. As of December 31, 2023, we have 2,189 employees and we operate four active mining complexes in the Illinois Basin. ​ Gibson Complex ​ Our subsidiary, Gibson, operates the Gibson South mine, located near the city of Princeton in Gibson County, Indiana. The Gibson South mine is an underground mine and utilizes continuous mining units employing room-and-pillar mining techniques to produce low/medium-sulfur coal. The Gibson South mine's preparation plant has throughput capacity of 1,800 tons of raw coal per hour. Production from the Gibson South mine is shipped by truck or transported by rail on the CSX or NS railroads from our rail loadout facility directly to customers or various transloading facilities, including our Mt. Vernon transloading facility, for barge delivery. Production from the mine began in April 2014. Gibson production in 2023 was 5.3 million tons. ​ River View Complex ​ Our subsidiary, River View, operates the River View mine and the Henderson County mine. The River View mine is located in Union County, Kentucky and is currently the largest room-and-pillar coal mine in the United States. The River View mine began production in 2009 and utilizes continuous mining units to produce medium/high-sulfur coal from multiple seams. The Henderson County mine is located in Henderson County, Kentucky and is currently under development, with full production expected to begin in 2024 from the No. 9 seam. ​ Both mines will utilize the existing preparation plant, refuse disposal, and loadout facilities. River View's preparation plant has throughput capacity of 2,700 tons of raw coal per hour. Coal produced from the River View complex is transported by overland belt to a barge loading facility on the Ohio River. River View coal production in 2023 was 9.9 million tons. ​ Hamilton Complex ​ Our subsidiary, Hamilton, operates the Hamilton mine, located near the city of McLeansboro in Hamilton County, Illinois. The Hamilton mine is an underground longwall mining operation producing medium/high-sulfur coal. Longwall mining began in October 2014 and we acquired complete ownership and control in 2015. Hamilton's preparation plant has throughput capacity of 2,000 tons of raw coal per hour. Hamilton has the ability to ship coal from the Hamilton mine via the CSX, Evansville Western Railway, or NS rail directly to customers or various transloading facilities, including our Mt. Vernon transloading facility, for barge deliveries. Hamilton coal production in 2023 was 5.6 million tons. ​ Warrior Complex ​ Our subsidiary, Warrior, operates an underground mining complex located near the city of Madisonville in Hopkins County, Kentucky. The Warrior complex was opened in 1985, and we acquired it in February 2003. Warrior utilizes continuous mining units employing room-and-pillar mining techniques to produce medium/high-sulfur coal. Warrior's preparation plant has throughput capacity of 1,200 tons of raw coal per hour. Warrior's production is shipped via the CSX or PAL railroads or by truck directly to customers or potentially to various transloading facilities, including our Mt. Vernon transloading facility, for barge deliveries. Warrior coal production in 2023 was 4.4 million tons. ​ 6 Table of Contents Mt. Vernon Transfer Terminal, LLC ​ Our subsidiary, Mt. Vernon, leases land and operates a coal-loading terminal on the Ohio River at Mt. Vernon, Indiana. Coal is delivered to Mt. Vernon by both rail and truck. The terminal has a capacity of 8.0 million tons per year with existing ground storage of approximately 200,000 tons. In 2023, the terminal loaded approximately 3.6 million tons for customers of Gibson and Hamilton. ​ Appalachian Operations ​ Our Appalachian mining operations are located in eastern Kentucky, Maryland, and West Virginia. As of December 31, 2023, we had 1,014 employees and we operate three mining complexes in Appalachia. ​ Tunnel Ridge Complex ​ Our subsidiary, Tunnel Ridge, operates the Tunnel Ridge mine, an underground longwall mine in the Pittsburgh No. 8 coal seam, located near Wheeling, West Virginia. Longwall mining operations began at Tunnel Ridge in May 2012. The Tunnel Ridge preparation plant has throughput capacity of 2,000 tons of raw coal per hour. Coal produced from the Tunnel Ridge mine is medium/high-sulfur coal and is transported by conveyor belt to a barge loading facility on the Ohio River. Tunnel Ridge has the ability through a third-party facility to transload coal from barges for rail shipment on the Wheeling and Lake Erie Railway with connections to the CSX and the NS railroads. Tunnel Ridge coal production in 2023 was 7.7 million tons. ​ Mettiki Complex ​ The Mettiki Complex comprises the Mountain View mine located in Tucker County, West Virginia operated by our subsidiary Mettiki (WV) and a preparation plant located near the city of Oakland in Garrett County, Maryland operated by our subsidiary Mettiki (MD). Mettiki (WV) began longwall mining in November 2006. The Mountain View mine produces low/medium-sulfur coal, which is transported by truck either to the Mettiki (MD) preparation plant for processing for shipment into the metallurgical coal market or otherwise, or directly to the coal blending facility at the Virginia Electric and Power Company Mt. Storm Power Station. The Mettiki (MD) preparation plant has throughput capacity of 1,350 tons of raw coal per hour. Coal processed at the preparation plant can be trucked to the blending facility at Mt. Storm or shipped via the CSX railroad, which provides the opportunity to ship into the domestic and international thermal and metallurgical coal markets. Mettiki WV coal production in 2023 was 0.8 million tons. ​ MC Mining Complex ​ The MC Mining Complex is located near the city of Pikeville in Pike County, Kentucky. We acquired the original mine in 1989. Our subsidiary, MC Mining, through our subsidiary, Excel operates the Excel Mine No. 5. Excel completed the development of Mine No. 5 in May 2020 and transitioned its employees and equipment from Mine No. 4 in July 2020. The underground operation utilizes continuous mining units employing room-and-pillar mining techniques to produce low-sulfur coal. The existing preparation plant, which has throughput capacity of 1,000 tons of raw coal per hour, is utilized by Mine No. 5. Substantially all of the coal produced at MC Mining in 2023 met or exceeded the compliance requirements of Phase II of the Federal CAA (see "—Environmental, Health and Safety Regulations— Air Emissions " below). Coal produced from the mine is shipped via the CSX railroad directly to customers or various transloading facilities on the Ohio River for barge deliveries, or by truck directly to customers or various docks on the Big Sandy River for barge deliveries. MC Mining coal production in 2023 was 1.2 million tons. ​ Coal Marketing and Sales ​ We sell coal to an established customer base through opportunities as a result of existing business relationships or through formal bidding processes. As is customary in the coal industry, we have entered into long-term coal supply agreements with many of our customers. These arrangements are mutually beneficial to our customers and us in that they provide greater predictability of sales volumes and sales prices. Although some utility customers have appeared to favor a shorter-term contracting strategy, in 2023 approximately 93.4% and 92.0% of our sales tonnage and total coal sales, respectively, were sold under long-term contracts with committed term expirations ranging from 2024 to 2029. Our initial 2024 guidance includes 32.5 million priced and committed tons for delivery in 2024. The contractual time commitments 7 Table of Contents for customers to nominate future purchase volumes under these contracts are typically sufficient to allow us to balance our sales commitments with prospective production capacity. ​ The provisions of long-term contracts are the results of both bidding procedures and extensive negotiations with each customer. As a result, the provisions of these contracts vary significantly in many respects, including, among other factors, price adjustment features, price, and contract reopener terms, permitted sources of supply, force majeure provisions, and coal qualities and quantities. A portion of our long-term contracts is subject to price adjustment provisions, which periodically permit an increase or decrease in the contract price, typically to reflect changes in specified indices or changes in production costs resulting from regulatory changes, or both. These provisions, however, may not ensure that the contract price will reflect every change in production or other costs. Failure of the parties to agree on a price pursuant to an adjustment or a reopener provision can, in some instances, lead to the early termination of a contract. Some of the long-term contracts also permit the contract to be reopened for renegotiation of terms and conditions other than pricing terms, and where a mutually acceptable agreement on terms and conditions cannot be concluded, either party may have the option to terminate the contract. Long-term contracts typically stipulate procedures for the transportation of coal, quality control, sampling, and weighing. Most contain provisions requiring us to deliver coal within stated ranges for specific coal characteristics such as heat, sulfur, ash, moisture, grindability, volatility, and other qualities. Failure to meet these specifications can result in economic penalties, rejection or suspension of shipments, or termination of the contracts. While most of the contracts specify the approved seams and/or approved locations from which the coal is to be mined, some contracts allow the coal to be sourced from more than one mine or location. Although the volume to be delivered pursuant to a long-term contract is stipulated, the buyers often have the option to vary the volume within specified limits. Coal contracts typically contain force majeure provisions allowing for the suspension of performance by either party for the duration of specified events. Force majeure events include but are not limited to unexpected significant geological conditions and weather events that may disrupt transportation. Depending on the language of the contract, some contracts may terminate upon an event of force majeure that extends for a certain period. ​ The international coal market has been a part of our business with indirect sales to end-users in Europe, Africa, Asia, North America, and South America. Our sales into the international coal market are considered exports and the majority are made through brokered transactions. During the years ended December 31, 2023, 2022, and 2021, export tons represented approximately 15.7%, 12.5%, and 12.5% of tons sold, respectively. Because title to our export shipments typically transfers to our brokerage customers at a point that does not necessarily reflect the end-usage point, we attribute export tons to the country with the end-usage point, if known. ​ Reliance on Major Customers ​ In 2023, we derived more than 10% of our total revenue from each of American Electric Power and Tennessee Valley Authority. We did not derive 10% or more of our revenues from any other single customer. For more information about these customers, please read "Item 8. Financial Statement and Supplemental Data—Note 22 – Concentration of Credit Risk and Major Customers." ​ Coal Competition ​ The coal industry is intensely competitive. The most important factors on which we compete are coal price, coal quality (including sulfur and heat content), reliability and diversity of supply, and transportation costs from the mine to the customer. We are the largest coal producer in the eastern United States. Our principal competitors include American Consolidated Natural Resources Inc., CONSOL Energy, Inc., Alpha Metallurgical Resources, Inc., Foresight Energy LP, and Peabody Energy Corporation. We also compete directly with smaller producers in the Illinois Basin and Appalachian regions. In addition, we seek to export a portion of our coal into the international coal markets and we compete with companies that produce coal from one or more foreign countries. ​ The price per ton for our export coal sales is influenced by many factors, such as global economic conditions, weather patterns, and global supply and demand, among others. The price per ton for our domestic coal sales are primarily linked to coal consumption patterns of domestic electricity-generating utilities, which in turn are influenced by economic activity, government regulations, weather, and technological developments, as well as the location, quality, price and availability of competing sources of fuel and alternative energy sources such as natural gas, nuclear energy, petroleum and renewable energy sources for electrical power generation. ​ For additional information, please see "Item 1A. Risk Factors." 8 Table of Contents ​ Coal Transportation ​ Our coal is transported from our mining complexes to our customers by barge, rail, and truck, reflecting important flexibility advantages in supplying our customers. Depending on the proximity of the customer to the mining complex and the transportation available for delivering coal to that customer, transportation costs can be a substantial part of the total delivered cost of a customer's coal. Consequently, the availability and cost of transportation constitute important factors in the marketability of coal. We believe our mines are located in favorable geographic locations that minimize transportation costs for our customers, and in many cases, we can accommodate multiple transportation options. Our customers typically negotiate and pay the transportation costs from the mining complex to the destination, which is the standard practice in the industry. Approximately 50.2% of our 2023 sales volume was initially shipped from the mining complexes by barge, 32.1% was shipped from the mining complexes by rail, and 17.7% was shipped from the mining complexes by truck. The rates set by and available capacity of the transportation company serving a particular mine or customer may affect, either adversely or favorably, our marketing efforts concerning coal produced from the relevant mining complex. With respect to our export volumes from the United States to other countries, we generally sell coal to our customers at an export terminal in the United States and we are responsible for the cost of transporting coal to the export terminals. Our export customers generally negotiate and pay for ocean vessel transportation. ​ Mineral Interest Activities ​ Our mineral interest activities include both oil & gas and coal mineral interests. Our oil & gas mineral interest business includes all activities related to the oil & gas mineral interests held directly or indirectly by Alliance Minerals and includes Alliance Minerals' equity interest in AllDale III. Our mineral interests are primarily located on private lands in three basins, which are also our areas of focus for future development by operators. These include the Permian (Delaware and Midland), Anadarko (SCOOP/STACK), and Williston (Bakken) Basins. Our developed and undeveloped net acres standardized to a 1/8th royalty equate to more than 67,745 oil & gas net royalty acres, including 3,969 oil & gas net royalty acres owned through our equity interest in AllDale III. ​ Our coal mineral interests include substantially all of our coal mineral resources and 557.7 million tons of coal mineral reserves which are owned or leased by Alliance Resource Properties and are (a) leased or subleased to internal mining complexes or (b) near other internal and external coal mining operations but not yet leased. Our coal mineral interests are located in both the Illinois Basin and the Appalachia Basin. ​ Oil & Gas Royalties ​ When our oil & gas mineral interests are leased, we typically receive an upfront cash payment, known as a lease bonus, and we retain a mineral royalty, which entitles us to receive a fixed percentage of the revenue or production from the oil & gas produced from the acreage underlying our interests, free of lease operating expenses and capital costs. A lessee can extend the lease beyond the initial lease term with continuous drilling, production, or other operating activities, or by making an extension payment. When production or drilling ceases, the lease terminates, allowing us to lease the exploration and development rights to another party. As an owner of mineral interests, we incur the initial cost to acquire our interests but thereafter only incur our proportionate share of production and ad valorem taxes. Unlike owners of working interests in oil & gas properties, we are not obligated to fund drilling and completion costs, lease operating expenses, or plugging and abandonment costs associated with oil & gas production. ​ The following chart summarizes the production of our oil & gas mineral interests for the year ended December 31, 2023, 2022, and 2021, not including our equity interest in AllDale III: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2023 ​ 2022* ​ 2021* Production: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Oil (MBbls) ​ ​ 1,418 ​ ​ 1,061 ​ ​ 898 ​ Natural gas (MMcf) ​ ​ 5,759 ​ ​ 4,814 ​ ​ 3,460 ​ Natural gas liquids (MBbls) ​ ​ 726 ​ ​ 541 ​ ​ 402 ​ BOE (MBbls) ​ ​ 3,105 ​ ​ 2,404 ​ ​ 1,877 ​ * Recast to reflect the JC Resources Acquisition as if we, rather than JC Resources, acquired the mineral interests in 2019. Please see "Item 8. Financial Statement and Supplemental Data—Note 1 – Organization and Presentation and Note 3 – Acquisitions" for more information. ​ 9 Table of Contents ​ The following map shows the location of our oil & gas mineral interests: ​ ​ Permian Basin—Delaware and Midland Basins ​ The Permian Basin ranges from West Texas into southeastern New Mexico and is currently the most active area for horizontal drilling in the United States. The Permian Basin is further subdivided into the Delaware Basin in the west and the Midland Basin in the east. Based on geologic data and the ongoing development by operators, our mineral interests in the Permian Basin contain multiple producing zones of economic horizontal development including but not limited to the Wolfcamp, Spraberry, and Bone Spring formations. Our purchases of acreage located entirely in the Permian Basin through the Belvedere, Jase and JC Resources Acquisitions demonstrate our commitment to continued acquisition of mineral interests in the nation's highest growth oil & gas plays. ​ Anadarko Basin—SCOOP and STACK Plays ​ The SCOOP play (South Central Oklahoma Oil Province) is located in central Oklahoma in Grady, Garvin, Stephens, and McClain Counties. Based on geologic data and the ongoing development by operators, our mineral interests in the SCOOP play contain multiple producing zones of economic horizontal development including multiple Woodford benches and the Springer Shale. In addition, operators are also currently testing other formations in the area including the Sycamore, Caney, and Osage, which is also referred to as SCORE (Sycamore Caney Osage Resource Expansion). The STACK play (derived from Sooner Trend, Anadarko Basin, Canadian and Kingfisher Counties) is located in central Oklahoma in Kingfisher, Canadian, Caddo, and Blaine Counties. Based on geologic data and the ongoing development by operators, our mineral interests in the STACK play contain multiple producing zones of economic horizontal development including but not limited to the Meramec and Woodford formations. ​ 10 Table of Contents Williston Basin—Bakken ​ The Williston Basin stretches from western North Dakota into eastern Montana. Based on geologic data and ongoing development by operators, our mineral interests contain multiple producing zones of economic horizontal development including the Bakken and Three Forks formations. ​ Other ​ Our other interests are comprised primarily of mineral interests owned in the Appalachia Basin that stretches throughout most of Ohio, West Virginia, and Pennsylvania, and extends into other states. The Appalachia Basin's most active plays in which we have acreage are the Marcellus Shale and Utica plays, which cover most of Pennsylvania, northern West Virginia, and eastern Ohio. In addition to the interests held in the Appalachia Basin, we own a small number of mineral interests in the Tuscaloosa Marine Shale play in Mississippi. AllDale III also owns mineral interests in the Haynesville Shale formation located in northwest Louisiana. ​ Coal Royalties ​ Our Coal Royalties segment includes approximately 557.7 million tons of reserves and substantially all of the 1.06 billion tons of our coal mineral resources. Our coal mineral reserves and resources are located in the Appalachia and Illinois Basins in the United States. We lease our reserves and resources to our mining complexes under long-term leases. Approximately 60% of our royalty-based leases have initial terms of five to 40 years, with substantially all lessees having the option to extend the lease for additional terms. ​ Under our standard royalty lease, we grant the lessees the right to mine and sell our reserves and resources in exchange for royalty payments based on a percentage of the sale price or a fixed royalty per ton of coal mined and sold. Lessees calculate royalty payments due to us and are required to report tons of coal mined and sold as well as the sales prices of the extracted coal. ​ The following chart summarizes the coal sales associated with our coal mineral interests for the years ended December 31, 2023, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Coal Regions 2023 2022 2021 ​ ​ (tons in millions) Illinois Basin 19.9 21.2 18.9 ​ Appalachia 0.3 0.6 1.3 ​ Total 20.2 21.8 20.2 ​ ​ 11 Table of Contents The following map shows the location of our coal mineral interests: ​ ​ ​ ​ ​ ​ ​ Illinois Basin: ​ ​ Appalachian Basin: ​ A. GIBSON RESERVES AND RESOURCES ​ E. HENDERSON/UNION RESOURCES ​ H. TUNNEL RIDGE RESERVES AND RESOURCES ​ B. HAMILTON RESERVES AND RESOURCES ​ F. DOTIKI RESOURCES ​ I. MOUNTAIN VIEW RESERVES AND RESOURCES ​ C. RIVER VIEW RESERVES ​ G. SEBREE SOUTH RESOURCES ​ J. PENN RIDGE RESOURCES ​ ​ D. WARRIOR RESERVES ​ ​ ​ ​ ​ ​ Illinois Basin ​ Alliance Resource Properties, either directly or through its subsidiaries, holds coal mineral reserves and resources in the following counties in the Illinois Basin: ​ ● Hopkins County, Kentucky ● Webster County, Kentucky ● Union County, Kentucky ● Henderson County, Kentucky ● Hamilton County, Illinois ● Gibson County, Indiana ​ Alliance Resource Properties leases some of the reserves and resources in Union and Henderson Counties from WKY CoalPlay or its subsidiaries, which are related parties. For more information about our WKY CoalPlay transactions, please read "Item 8. Financial Statements and Supplementary Data—Note 20 – Related-Party Transactions." ​ Approximately 477.0 million tons of proven and probable reserves and 977.2 million tons of measured, indicated and inferred coal mineral resources are controlled by Alliance Resource Properties in the Illinois Basin and are leased/subleased to our mining complexes or held for lease/sublease in the future as follows: ​ 12 Table of Contents Gibson Reserves and Resources ​ Approximately 4.4 million tons of the reserves and resources are currently leased/subleased or held for lease/sublease to our subsidiary, Gibson. ​ Hamilton Reserves and Resources ​ Approximately 564.5 million tons of the reserves and resources are currently leased/subleased or held for lease/sublease to our subsidiary, Hamilton. ​ River View Reserves ​ Approximately 303.1 million tons of the reserves are currently leased/subleased or held for lease/sublease to our subsidiary, River View. ​ Warrior Reserves ​ Approximately 50.0 million tons of the reserves are currently leased/subleased or held for lease/sublease to our subsidiary, Warrior. ​ Henderson/Union Resources ​ Approximately 412.7 million tons of the resources are not under lease or currently anticipated to be leased by our operating companies. Leasing of these properties is dependent upon further development by our operating subsidiaries or third-party mining complexes, which is regulatory and market dependent. ​ Dotiki Resources ​ Approximately 76.0 million tons of the resources are currently leased/subleased or held for lease/sublease to our subsidiary, Webster. ​ Sebree South Resources ​ Approximately 43.5 million tons of the resources are currently leased/subleased to our subsidiary, Sebree. ​ Appalachia Basin ​ Alliance Resource Properties, either directly or through its subsidiaries, holds coal mineral reserves and resources in the following counties in the Appalachian Basin: ​ ● Brooke County, West Virginia ● Grant County, West Virginia ● Ohio County, West Virigina ● Tucker County, West Virginia ● Washington County, Pennsylvania ​ Approximately 80.7 million tons of reserves and 85.4 million tons of coal mineral resources are controlled by Alliance Resource Properties in the Appalachian Basin and are leased/subleased to our mining complexes or held for lease/sublease in the future as follows: ​ Tunnel Ridge Reserves and Resources ​ Approximately 75.0 million tons of the reserves and resources are currently leased/subleased or held for lease/sublease to our subsidiary, Tunnel Ridge. ​ 13 Table of Contents Mountain View Reserves and Resources ​ Approximately 13.1 million tons of the reserves and resources are currently leased/subleased or held for lease/sublease to our subsidiary, Mettiki (WV). ​ Penn Ridge Resources ​ Approximately 78.0 million tons of the resources are not under a lease. The resources are near our Tunnel Ridge mining complex and leasing of these resources is dependent upon further development by Tunnel Ridge or third-party mining complexes, which is regulatory and market dependent. ​ Minerals Interest Competition ​ Many companies are engaged in the search for and the acquisition of coal and oil & natural gas interests, and there is a limited supply of desirable coal and oil & natural gas reserves. Our ability to acquire additional oil & gas mineral interests in the future will be dependent upon our ability to evaluate and select suitable properties and to consummate transactions in a highly competitive environment. Many of our competitors not only own and acquire oil & gas mineral interests but also explore for and produce oil & gas and, in some cases, conduct midstream and refining operations and market petroleum and other products on a regional, national, or worldwide basis. By engaging in such other activities, our competitors may be able to develop or obtain information that is superior to the information that is available to us. In addition, because we have fewer financial and human resources than many companies in the oil & gas industry, we may be at a disadvantage in bidding for oil & gas properties. Further, oil & gas compete with other forms of energy available to customers, primarily based on price. These alternate forms of energy include electricity, coal, and fuel oils. Changes in the availability or price of oil & gas or other forms of energy, as well as business conditions, conservation, legislation, regulations, and the ability to convert to alternative fuels and other forms of energy, may affect the demand for oil & gas. ​ We also face competition from land companies, coal producers, and international steel companies in purchasing coal mineral reserves and resources as well as royalty-producing properties. Our mining complexes in which we lease our reserves compete with coal producers in various regions of the United States for domestic sales on the basis of coal price at the mine, coal quality, transportation cost from the mine to the customer, and the reliability of supply. Continued demand for our coal and the prices that our lessees obtain are also affected by the demand for electricity and steel, as well as government regulations, technological developments, and the availability and the cost of generating power from alternative fuel sources, including nuclear, natural gas, wind, solar, and hydroelectric power. ​ For additional information, please see "Item 1A. Risk Factors". ​ Oil & Gas Minerals Interest - Seasonal Nature of Business ​ Generally, demand for oil increases during the summer months and decreases during the winter months while demand for natural gas increases during the winter and summer months and decreases during the spring and fall months. Certain buyers of natural gas use natural gas storage facilities and purchase some of their anticipated winter requirements during the summer, which can lessen seasonal demand fluctuations. Seasonal weather conditions and lease stipulations can limit drilling and producing activities and other oil & gas operations in a portion of our leasing areas. These seasonal anomalies can pose challenges for the Operators in meeting well-drilling objectives and can increase competition for equipment, supplies, and personnel during the spring and summer months, which could lead to shortages and increase costs or delay operations. ​ Other Operations ​ Matrix Group ​ Matrix Group provides a variety of technology products and services for our mining operations and certain industrial and mining technology products and services to third parties around the world. Matrix Group's products and services include data network, communication and tracking systems, mining proximity detection systems, industrial collision avoidance systems, and data and analytics software. In addition, Matrix Design has entered into an agreement with Infinitum to jointly develop and distribute high-efficiency motors and advanced motor controllers designed specifically for the mining industry. Under the agreement, Matrix Design will integrate Infinitum's motor technology into mining equipment of our operating subsidiaries to provide performance validation in production environments for jointly 14 Table of Contents developed products and to improve our operational efficiency. Matrix Design will also work with Infinitum to market the jointly developed technology products to third parties worldwide. We acquired Matrix Design in September 2006. Over the past 15 years, Matrix Group has become a leader in collision avoidance and proximity detection technologies, providing safety and productivity solutions for mining companies worldwide, while extending its reach into other industrial applications. ​ Growth Investments and Opportunities ​ Our subsidiary, AROP II, LLC, and its subsidiary, AROP II Investments, LLC, makes strategic investments in attractive opportunities that support the advancement of energy and related infrastructure. We intend to pursue opportunities that leverage our core competencies and relationships with electric utilities, industrial customers, and federal and state governments. Our strategy is to continue to identify and make strategic investments in the advancement of energy and related infrastructure opportunities that may create new platforms for future lines of business with long-term growth and cash flow generation. As of December 31, 2023, we have made investments of $25 million in Ascend, $20 million in Francis, $66.6 million in Infinitum and $6.6 million (of a $25 million commitment) in NGP ET IV. In 2023, revenues from these investments were immaterial. ​ Ascend is a U.S.-based manufacturer and recycler of sustainable, closed-loop engineered battery materials for electric vehicles. Ascend is currently constructing North America's first commercial-scale manufacturing facility located near Hopkinsville, Kentucky, that when complete, will produce enough cathode materials for 750,000 electric vehicles per year. ​ Francis is currently active in the installation, management and operation of metered-for-fee, public-access EV charging stations. Francis also develops and contracts EV charging stations for third-party customers. ​ Infinitum is a Texas-based developer and manufacturer of electric motors featuring printed circuit board stators that have the potential to result in motors that are smaller, lighter, quieter, more efficient and capable of operating at a fraction of the carbon footprint of conventional electric motors. ​ NGP ET IV focuses on investments that are part of the global transition toward a lower carbon economy by partnering with top-tier management teams and investing growth equity in companies that drive or enable the growth of renewable energy, the electrification of our economy, or the efficient use of energy. ​ Environmental, Health, and Safety Regulations ​ Our coal operations, and those of the operators on the properties in which we hold oil & gas mineral interests, are subject to extensive regulation by federal, state, and local authorities on matters such as: ​ ● employee health and safety; ● permits and other licensing requirements for mining or exploration and production activities; ● air quality standards; ● water quality standards; ● storage of petroleum products and substances that are regarded as hazardous under applicable laws or that, if spilled, could reach waterways or wetlands; ● plant and wildlife protection that could limit or prohibit mining or exploration and production activities; ● restrict the types, quantities, and concentration of materials that can be released into the environment in the performance of mining or exploration and production activities; ● initiate investigatory and remedial measures to mitigate pollution from former or current operations, such as restoration of waste ponds, mining areas, drilling pits, and plugging of abandoned wells; ● storage and handling of explosives; ● wetlands protection; ● surface subsidence from underground mining; and ● the effects, if any, that mining has on groundwater quality and availability. ​ 15 Table of Contents Failure to comply with environmental laws and regulations may result in the assessment of administrative, civil, and criminal sanctions, including monetary penalties, the imposition of strict, joint and several liability, investigatory and remedial obligations, and the issuance of injunctions limiting or prohibiting some or all of the operations on our properties. The regulatory burden on fossil-fuel industries increases the cost of doing business and consequently affects profitability. The trend in environmental regulation has been to place more restrictions and limitations on activities that may affect the environment, and thus, any changes in environmental laws and regulations or reinterpretation of enforcement policies that result in more stringent and costly obligations could increase our or our mineral interest operators' costs and adversely affect our performance. ​ In addition, the utility industry is subject to extensive regulation regarding the environmental impact of its power generation activities, which has adversely affected the demand for coal. It is possible that new legislation or regulations may be adopted, or that existing laws or regulations may be differently interpreted or more stringently enforced, any of which could have a significant impact on our mining operations, our customers' ability to use coal, or the value of or amount of royalties received from our mineral interests. For more information, please see the risk factors described in "Item 1A. Risk Factors" below. ​ We are committed to conducting mining operations in compliance with applicable federal, state, and local laws and regulations. However, because of the extensive and detailed nature of these regulatory requirements, particularly the regulatory system of MSHA where citations can be issued without regard to fault and many of the standards include subjective elements, it is not reasonable to expect any coal mining company to be free of citations. When we receive a citation, we attempt to promptly remediate any identified condition. While we have not quantified all of the costs of compliance with applicable federal and state laws and associated regulations, those costs have been and are expected to continue to be significant. Compliance with these laws and regulations has substantially increased the cost of coal mining for domestic coal producers. ​ Expenditures for environmental matters have not been material in recent years. We have accrued for the present value of the estimated cost of asset retirement obligations and mine closings, including the cost of treating mine water discharge, when necessary. The accruals for asset retirement obligations and mine closing costs are based on permit requirements and the estimated costs and timing assumptions of asset retirement obligations and mine closing procedures. Although management believes it has made adequate provisions for all expected reclamation and other costs associated with mine closures, future operating results would be adversely affected if these accruals were insufficient. ​ Mining Permits and Approvals ​ Numerous governmental permits or approvals are required for mining operations. Applications for permits require extensive engineering and data analysis and presentation and must address a variety of environmental, health, and safety matters associated with a proposed mining operation. These matters include the manner and sequencing of coal extraction, the storage, use, and disposal of waste and other substances and impacts on the environment, the construction of water containment areas, and reclamation of the area after coal extraction. Meeting all requirements imposed by any of these authorities may be costly and time-consuming and may delay or prevent the commencement or continuation of mining operations. ​ The permitting process for certain mining operations can extend over several years and can be subject to administrative and judicial challenges, including by the public. Some required mining permits are becoming increasingly difficult to obtain in a timely manner, or at all. We cannot assure you that we will not experience difficulty or delays in obtaining mining permits in the future or that a current permit will not be revoked. ​ We are required to post bonds to secure performance under our permits. Under some circumstances, substantial fines, and penalties, including revocation of mining permits, may be imposed under the laws and regulations described above. Monetary sanctions and, in severe circumstances, criminal sanctions may be imposed for failure to comply with these laws and regulations. Regulations also provide that a mining permit can be refused or revoked if the permit applicant or permittee owns or controls, directly or indirectly through other entities, mining operations that have outstanding environmental violations. Although like other coal companies, we have been cited for violations in the ordinary course of our business, we have never had a permit suspended or revoked because of any violation, and the penalties assessed for these violations have not been material. ​ 16 Table of Contents Mine Health and Safety Laws ​ The operation of our mines is subject to FMSHA, and regulations adopted pursuant thereto. FMSHA imposes extensive and detailed safety and health standards on numerous aspects of mining operations, including training of mine personnel, mining procedures, blasting, the equipment used in mining operations, and numerous other matters. MSHA monitors and rigorously enforces compliance with these federal laws and regulations. In addition, most of the states where we operate have state programs for mine safety and health regulation and enforcement. Federal and state safety and health regulations affecting the coal mining industry are perhaps the most comprehensive and rigorous system in the United States for the protection of employee safety and have a significant effect on our operating costs. Although many of the requirements primarily impact underground mining, our competitors in all of the areas in which we operate are subject to the same laws and regulations. ​ FMSHA has been construed as authorizing MSHA to issue citations and orders pursuant to the legal doctrine of strict liability, or liability without fault, and FMSHA requires the imposition of a civil penalty for each cited violation. Negligence and gravity assessments, along with other factors, can result in the issuance of various types of orders, including orders requiring withdrawal from the mine or the affected area, and some orders can also result in the imposition of civil penalties. FMSHA also contains criminal liability provisions. For example, criminal liability may be imposed upon corporate operators who knowingly and willfully authorize, order, or carry out violations of the FMSHA, or its mandatory health and safety standards. ​ The MINER Act significantly amended the FMSHA, imposing more extensive and stringent compliance standards, increasing criminal penalties, and establishing a maximum civil penalty for non-compliance, and expanding the scope of federal oversight, inspection, and enforcement activities. Following the passage of the MINER Act, MSHA has issued new or more stringent rules and policies on a variety of topics, including: ​ ● sealing off abandoned areas of underground coal mines; ● mine safety equipment, training, and emergency reporting requirements; ● substantially increased civil penalties for regulatory violations; ● training and availability of mine rescue teams; ● underground "refuge alternatives" capable of sustaining trapped miners in the event of an emergency; ● flame-resistant conveyor belts, fire prevention and detection, and use of air from the belt entry; and ● post-accident two-way communications and electronic tracking systems. ​ MSHA continues to interpret and implement various provisions of the MINER Act, along with introducing new proposed regulations and standards. ​ MSHA has finalized a number of rules related to controlling exposure to coal mine dust, which has resulted in progressively stricter exposure limits imposed by MHSA regulations. These requirements impose a number of dust monitoring obligation and mine ventilation requirements on our operations. Compliance with these rules can result in increased costs on our operations, including, but not limited to, the purchasing of new equipment and the hiring of additional personnel to assist with monitoring, reporting, and recordkeeping obligations. MSHA previously published a request for information regarding engineering controls and best practices to lower miners' exposure to respirable coal mine dust; however, to date no further action has been taken and we cannot predict what actions, if any, MSHA may take in response to this information request. ​ MSHA has also published, and may continue to publish, various proposed rules or requests for information, which may result in additional rulemaking. For example: ​ ● In June 2016, MSHA published a request for information on Exposure of Underground Miners to Diesel Exhaust. Following a comment period that closed in November 2016 for this matter, MSHA received requests for MSHA and the National Institute for Occupational Safety and Health to hold a Diesel Exhaust Partnership to address the issues covered by MSHA's 2016 request for information. The comment period for the request for information for the Diesel Exhaust Partnership closed in September 2020 and it is uncertain whether this will result in additional rulemaking. ● In July of 2023, MSHA published a proposed rule on respirable crystalline silica, most commonly found in the mining environment through quartz. The proposed rule would amend the existing MSHA standards to lower the permissible exposure limit of respirable crystalline silica, as well as set forth new or revised standards for 17 Table of Contents exposure sampling, corrective actions, medical surveillance for metal and non-metal miners, and respiratory protection requirements. The comment period on the proposed rule ended in August of 2023 and the final rule is expected in April 2024. ● In November 2020, MSHA published a proposed rule to revise Testing, Evaluation, and Approval of Electric Motor-Driven Mine Equipment and Accessories within underground mining environments. The comment period for the proposed rule closed in December 2020 and the final rule is expected in August 2024. ● In September 2021, MSHA published a proposed rule requiring that mine operators employing six or more miners develop and implement a written safety program for mobile and powered haulage equipment at surface mines and surface areas of underground mines (Safety Program for Surface Mobile Equipment). The comment period for the proposed rule closed in November 2021. However, MSHA reopened the rulemaking record for additional public comments. A virtual hearing was held in January 2022 and the comment period closed in February 2022. The final rule was released in December 2023, with an effective date of January 19, 2024. All mines subject to the rule are required to develop, implement, and periodically update a written safety program for surface mobile equipment (excluding belt conveyors) at surface mines and surface areas of underground mines. Compliance with the rule must be achieved by July 17, 2024. ​ It is uncertain whether any of the above or other various proposed rules or requests for information would have material impacts on our operations or our costs of operation. ​ Subsequent to the passage of the MINER Act, Illinois, Kentucky, Pennsylvania, and West Virginia have enacted legislation addressing issues such as mine safety and accident reporting, increased civil and criminal penalties, and increased inspections and oversight. Additionally, state administrative agencies can promulgate administrative rules and regulations affecting our operations. Other states may pass similar legislation or administrative regulations in the future. ​ Some of the costs of complying with existing regulations and implementing new safety and health regulations may be passed on to our customers. Although we have not quantified the full impact, implementing and complying with these new federal and state safety laws and regulations have had, and are expected to continue to have, an adverse impact on our results of operations and financial position. ​ Black Lung Benefits Act ​ The BLBA requires businesses that conduct current mining operations to make payments of black lung benefits to current and former coal miners with black lung disease, to some survivors of a miner who dies from this disease, and to a trust fund for the payment of benefits and medical expenses under circumstances including where no responsible coal mine operator has been identified for claims. In addition, the BLBA provides that some claims for which coal operators not affiliated with us had previously been responsible are or will become obligations of the government trust funded by the excise tax referenced in this paragraph. The Federal government established such a trust fund and as of January 1, 2022, the trust fund was funded by an excise tax on industry-wide production of up to $0.50 per ton for underground-mined coal and up to $0.25 per ton for surface-mined coal, but not to exceed 2% of the applicable gross sales price. The Inflation Reduction Act of 2022 raised the excise tax, effective October 1, 2022, up to $1.10 per ton of coal from underground mines and up to $0.55 per ton of coal from surface mines, neither amount to exceed 4.4% of the gross sales price. The coal we sell into international markets is generally not subject to the excise tax referenced in this paragraph. The Company recognized expenses related to the BLBA excise tax of $30.5 million for the year ended December 31, 2023. ​ Workers ' Compensation and Black Lung ​ We provide income replacement and medical treatment for work-related traumatic injury claims as required by applicable state laws. Workers' compensation laws also provide for the potential compensation of survivors of workers who suffer employment-related deaths. We generally self-insure this potential expense using our actuary estimates of the cost of present and future claims. In addition, coal mining companies are subject to federal legislation and various state statutes for the payment of medical and disability benefits to eligible recipients related to coal worker's pneumoconiosis, or black lung. We also provide for these claims through self-insurance programs. The DOL's OWCP is responsible for authorizing coal mine operators to self-insure for federal black lung and for setting applicable security amounts. In January 2023, the OWCP issued a Notice of Proposed Rulemaking to update its regulations authorizing coal producers to self-insure and for determining appropriate security amounts, and announced that it plans to solicit public comments for that proposal. A change in requirements for security posted to self-insure black lung liabilities could result in the Company being required to post additional security for its obligations. Our pneumoconiosis benefits liability is calculated using the 18 Table of Contents service cost method based on the actuarial present value of the estimated pneumoconiosis benefits obligation. Our actuarial calculations are based on numerous assumptions including disability incidence, medical costs, mortality, death benefits, dependents, and discount rates. For more information concerning our requirement to maintain bonds to secure our workers' compensation obligations, see the discussion of surety bonds below under "—Bonding Requirements." ​ The Patient Protection and Affordable Care Act, enacted in 2010, includes significant changes to the federal black lung program retroactive to 2005, including an automatic survivor benefit paid upon the death of a miner with an awarded black lung claim and establishes a rebuttable presumption with regard to pneumoconiosis among miners with 15 or more years of coal mine employment that are totally disabled by a respiratory condition. These changes have caused a significant increase in our costs expended in association with the federal black lung program. We may also be liable under various state statutes with respect to black lung claims. ​ Surface Mining Control and Reclamation Act ​ The SMCRA and similar state statutes establish operational, reclamation, and closure standards for all aspects of surface mining as well as many aspects of deep mining. Although we have minimal surface mining activity and no mountaintop removal mining activity, SMCRA nevertheless requires that comprehensive environmental protection and reclamation standards be met during the course of and upon completion of our mining activities. ​ SMCRA and similar state statutes require, among other things, that mined property be restored in accordance with specified standards and approved reclamation plans. SMCRA requires us to restore the surface to approximate the original contours as contemporaneously as practicable with the completion of surface mining operations. Federal law and some states impose on mine operators the responsibility for replacing certain water supplies damaged by mining operations and repairing or compensating for damage to certain structures occurring on the surface as a result of mine subsidence, a consequence of longwall mining and possibly other mining operations. We believe we are in compliance in all material respects with applicable regulations relating to reclamation. We have accrued $150.4 million for the estimated costs of reclamation and mine closing, including the cost of treating mine water discharge when necessary. Please read "Item 8. Financial Statements and Supplementary Data—Note 18 – Asset Retirement Obligations." ​ In addition, the Abandoned Mine Lands Program, which is part of SMCRA and relates to industry-wide operations, imposes a reclamation fee on all current mining operations, the proceeds of which are used to restore mines closed before 1977. The fee expired on September 30, 2021, and was reauthorized through September 30, 2034, under the Infrastructure Investment and Jobs Act which was signed on November 15, 2021. The fee, as reauthorized, for surface-mined and underground-mined coal is $0.224 per ton and $0.096 per ton, respectively, through September 30, 2034. In addition, states from time to time have increased and may continue to increase their fees and taxes to fund reclamation or orphaned mine sites and acid mine drainage control on a statewide basis. ​ Under SMCRA, responsibility for unabated violations, unpaid civil penalties, and unpaid reclamation fees of independent contract mine operators and other third parties can be imputed to other companies that are deemed, according to the regulations, to have "owned" or "controlled" the third-party violator. Sanctions against the "owner" or "controller" are quite severe and can include being blocked from receiving new permits and having any permits revoked that were issued after the time of the violations or after the time civil penalties or reclamation fees became due. We are not aware of any currently pending or asserted claims against us relating to the "ownership" or "control" theories discussed above. However, we cannot assure you that such claims will not be asserted in the future. ​ Bonding Requirements ​ Federal and state laws require bonds to secure our obligations to reclaim lands used for mining, to pay federal and state workers' compensation, to pay certain black lung claims, and to satisfy other miscellaneous obligations. These bonds are typically renewable on a yearly basis. It has become increasingly difficult for us and for our competitors to secure new surety bonds without posting collateral and in some cases it is unclear what level of collateral will be required. In addition, surety bond costs have increased while the market terms of surety bonds have generally become less favorable to us. It is possible that surety bond issuers may refuse to renew bonds or may demand additional collateral upon those renewals. Our failure to maintain or inability to acquire, surety bonds that are required by federal and state laws would have a material adverse effect on our ability to produce coal, which could affect our profitability and cash flow. For additional information, please see "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources— Cash Requirements ." 19 Table of Contents ​ Air Emissions ​ The CAA and similar state and local laws and regulations regulate emissions into the air and affect coal mining, as well as oil & gas, operations. The CAA imposes permitting requirements and, in some cases, requirements to install certain emissions control equipment, achieve certain emissions standards, or implement certain work practices on sources that emit various air pollutants. The CAA also indirectly affects coal mining operations by extensively regulating the air emissions of coal-fired electric power generating plants and other coal-burning facilities. There has been a series of federal rulemakings focused on emissions from coal-fired electric generating facilities. Installation of additional emissions control technology and any additional measures required under applicable federal and state laws and regulations related to air emissions will make it more costly to operate coal-fired power plants and possibly other facilities that consume coal and, depending on the requirements of SIPs, could make fossil fuels a less attractive fuel alternative in the planning and building of power plants in the future. A significant reduction in fossil fuels' share of power generating capacity could have a material adverse effect on our business, financial condition, and results of operations. ​ In addition to the GHG issues discussed below, the air emissions programs that may affect our operations or the operations of those on the properties in which we hold mineral interests, directly or indirectly, include but are not limited to the following: ​ ● The EPA ' s Acid Rain Program, provided in Title IV of the CAA, regulates emissions of sulfur dioxide from electric generating facilities. Sulfur dioxide is a by-product of coal combustion. Affected facilities purchase or are otherwise allocated sulfur dioxide emissions allowances, which must be surrendered annually in an amount equal to a facility ' s sulfur dioxide emissions in that year. Affected facilities may sell or trade excess allowances to other facilities that require additional allowances to offset their sulfur dioxide emissions. In addition to purchasing or trading for additional sulfur dioxide allowances, affected power facilities can satisfy the requirements of the EPA ' s Acid Rain Program by switching to lower-sulfur fuels, installing pollution control devices such as flue gas desulfurization systems, or " scrubbers, " or by reducing electricity-generating levels. In 2023, we sold 80.9% of our total tons to electric utilities in the United States, substantially all of which was sold to utility plants with installed pollution control devices. These requirements would not be supplanted by a replacement rule for the CAIR, discussed below. ​ ● The CAIR called for power plants in 28 states and Washington, D.C. to reduce emission levels of sulfur dioxide and nitrogen oxide pursuant to a cap-and-trade program similar to the system in effect for acid rain. In June 2011, the EPA finalized the CSAPR, a replacement rule for CAIR, which would have required twenty-eight states in the Midwest and eastern seaboard to reduce power plant emissions that cross state lines and contribute to ozone and/or fine particle pollution in other states. CSAPR has become increasingly irrelevant with continuing coal plant retirements making the nitrogen oxide ozone budget less stringent and lowering emission allowance prices to levels closer to average operating cost for many of our customers. The full impacts of CSAPR are presently unknown due to the implementation of MATS, discussed below, and the impact of the continuing coal plant retirements. ​ ● In May 2020, EPA issued a final rule that reversed the Agency’s prior determination from 2000 to 2016 that it was " appropriate and necessary " to regulate hazardous air pollutants from coal-fueled EGUs under the MATS rule, which regulates the emission of mercury and other metals, fine particulates, and acid gases such as hydrogen chloride from coal and oil-fired power plants. However, in February 2023, EPA published a final revocation of the May 2020 finding. Then, in April 2023, the EPA issued a proposed rule to amend the MATS rule, to reflect developments in control technologies and plant performance. Although the impacts of the potential final rule are unknown, the MATS rule has forced electric power generators to make capital investments to retrofit power plants and could lead to additional premature retirements of older coal-fired generating units and many electric power generators have already announced retirements due to the uncertainty surrounding the MATS rule. The announced and possible additional retirements are likely to reduce the demand for coal. Apart from MATS, several states have enacted or proposed regulations requiring reductions in mercury emissions from coal-fired power plants, and federal legislation to reduce mercury emissions from power plants has been proposed. Regulation of mercury emissions by the EPA, states, or Congress may decrease the future demand for coal. We continue to evaluate the possible scenarios associated with CSAPR updates and MATS and the effects they may have on our business and our results of operations, financial condition, or cash flows. 20 Table of Contents ​ ● The CAA requires the EPA to periodically reevaluate the available health effects information to determine whether the NAAQS should be revised. Pursuant to this process, the EPA has adopted more stringent NAAQS for fine PM, ozone, nitrogen oxide, and sulfur dioxide. As a result, some states will be required to amend their existing SIPs to attain and maintain compliance with the new air quality standards and other states will be required to develop new SIPs for areas that were previously in "attainment" but do not attain the new standards. In addition, under the revised ozone NAAQS, significant additional emissions control expenditures may be required at coal-fired power plants. In March 2019, the EPA published a final rule that retained the current primary NAAQS for sulfur oxide. In December 2020, EPA published a final rule to retain the current NAAQS for both PM and ozone; however, various entities filed litigation against one or both of these rulemakings, and the Biden Administration announced that it would reconsider and potentially revise the NAAQS. With respect to ozone, a draft assessment released in April 2022 indicated a preliminary conclusion that the December 2020 decision would stand. However, on August 21, 2023, the EPA announced a new review of the ozone NAAQS to reflect updated ozone science in combination with the reconsideration of the December 2020 decision. The Agency is expected to release its Integrated Review Plan in the fall of 2024. New standards may impose additional emissions control requirements on new and expanded coal-fired power plants and industrial boilers. Because coal mining operations and coal-fired electric generating facilities emit particulate matter and sulfur dioxide, our mining operations and our customers could be affected when the new standards are implemented by the applicable states, and developments could indirectly reduce the demand for coal. Separately, the implementation of new standards by states has the potential to delay or otherwise impact oil & gas production activities, which could reduce the profitability of our mineral interests. ​ ● The EPA ' s regional haze program is designed to protect and improve visibility at and around national parks, national wilderness areas, and international parks. Under the program, states are required to develop SIPs to improve visibility. Typically, these plans call for reductions in sulfur dioxide and nitrogen oxide emissions from coal-fueled electric plants. In prior cases, the EPA has decided to negate the SIPs and impose stringent requirements through FIPs. The regional haze program, including particularly the EPA ' s FIPs, and any future regulations may restrict the construction of new coal-fired power plants whose operation may impair visibility at and around federally protected areas and may require some existing coal-fired power plants to install additional control measures designed to limit haze-causing emissions. These requirements could limit the demand for coal in some locations. In September 2018, the EPA issued a memorandum that detailed plans to assist states as they develop their SIPs, which was followed by a supplemental memorandum in July 2021 for SIPs for the second implementation period. ​ ● The EPA ' s NSR program under the CAA in certain circumstances requires existing coal-fired power plants, when modifications to those plants significantly increase emissions, to install more stringent air emissions control equipment. The Department of Justice, on behalf of the EPA, has filed lawsuits against a number of coal-fired electric generating facilities alleging violations of the NSR program. The EPA has alleged that certain modifications have been made to these facilities without first obtaining certain permits issued under the program. Several of these lawsuits have been settled, but others remain pending. In October 2020, the EPA finalized a rule to clarify the process for evaluating whether the NSR permitting program would apply to a proposed modification of a source of air emissions. The EPA has announced that it will review the NSR program. Depending on the ultimate resolution of the EPA's litigation and review, demand for coal could be affected. ​ ● The EPA's NSPS under the CAA require the reduction of certain pollutants and methane emissions from certain stimulated oil & gas wells for which well completion operations are conducted and further require that most wells use reduced emission completions, also known as "green completions." These regulations also establish specific new requirements regarding emissions from production-related wet seal and reciprocating compressors, and pneumatic controllers and storage vessels. Although the Trump Administration revised prior regulations in September 2020 to rescind certain methane standards and remove the transmission and storage segments from the source category for certain regulations, the U.S. Congress passed, and President Biden signed into law, a revocation of the 2020 rulemaking, effectively reinstating the 2016 standards. In December 2023, EPA issued its final methane rules, known as OOOOb and OOOOc, that establish new source and first-time existing source standards of performance for GHG and VOC emissions for crude oil and natural gas well sites, natural gas gathering and boosting compressor stations, natural gas 21 Table of Contents processing plants, and transmission and storage facilities. The final rules include nationwide emissions guidelines for states to limit methane emissions from existing crude oil and natural gas facilities and states have two years to prepare and submit their plans to impose methane emission controls on existing sources. The rules also revise requirements for fugitive emissions monitoring and repair as well as equipment leaks and the frequency of monitoring surveys and establishes a "super-emitter" response program to timely mitigate emissions events. It is likely that the final rule and its requirements will be subject to legal challenges. Moreover, compliance with the new rules may effect the amount oil & gas companies owe under the Inflation Reduction Act, which amended the CAA to impose a first-time fee on the emission of methane from sources required to report their GHG emissions to the EPA. The methane emissions fee applies to excess methane emissions from certain facilities and starts at $900 per metric ton of leaked methane in 2024 and increases to $1,200 in 2025 and $1,500 in 2025 and thereafter. Compliance with the EPA’s new final rules would exempt an otherwise covered facility from the requirement to pay the methane fee. Oil & gas production on the properties in which we hold mineral interests could be adversely affected to the extent the rules and any of their requirements impose increased operating costs on the oil & gas industry. ​ GHG Emissions ​ Combustion of fossil fuels, such as the coal we produce and the oil & gas produced from our mineral interests, results in the emission of GHGs, such as carbon dioxide and methane. Combustion of fuel for mining equipment used in coal production also emits GHGs. Future regulation of GHG emissions in the United States could occur pursuant to future United States treaty commitments, new or existing domestic legislation, or regulation by the EPA. Although no comprehensive climate change regulation has been adopted at the federal level in the United States, President Biden has made it clear that climate change will be a focus of his administration. For example, in January 2021, President Biden issued an executive order that commits to substantial action on climate change, calling for, among other things, the increased use of zero-emissions vehicles by the federal government, the elimination of subsidies provided to the fossil-fuel industry, a doubling of electricity generated by offshore wind by 2030, and increased emphasis on climate-related risks across governmental agencies and economic sectors. Internationally, the Paris Agreement requires member states to submit non-binding, individually determined emissions reduction targets. These commitments could further reduce demand and prices for fossil fuels. President Biden recommitted the United States to the Paris Agreement in February 2021 and, in April 2021, announced a new, more rigorous nationally determined emissions reduction level of 50-52% reduction from 2005 levels in economy wide net GHG emissions by 2030. The international community gathered again at the COP26 during which multiple announcements were made, including a call for parties to eliminate fossil fuel subsidies, among other measures. Relatedly, the United States and European Union jointly announced at COP26 the launch of the Global Methane Pledge, an initiative committing to a collective goal of reducing global methane emissions by at least 30% from 2020 levels by 2030, including "all feasible reductions" in the energy sector. Also at COP26, more than forty countries pledged to phase out coal, although the United States did not sign the pledge. In December 2023, the United Arab Emirates hosted the COP28 where parties signed onto an agreement to transition "away from fossil fuels in energy systems in a just, orderly and equitable manner" and increase renewable energy capacity so as to achieve net zero by 2050, although no timeline for doing so was set. The full impact of these actions remains unclear at this time. Moreover, many states, regions, and governmental bodies have adopted GHG initiatives and have or are considering the imposition of fees or taxes based on the emission of GHGs by certain facilities, including coal-fired electric generating facilities. Others have announced their intent to increase the use of renewable energy sources, displacing coal, and other fossil fuels. Depending on the particular regulatory program that may be enacted, at either the federal or state level, the demand for coal and oil & gas could be negatively impacted, which would have an adverse effect on our operations. ​ The EPA has begun to regulate GHG emissions from stationary sources, such as coal-fueled power plants, under existing federal CAA. In August 2015, the EPA issued its final CPP Rule, which established carbon pollution standards for power plants. The CPP was subsequently challenged by multiple states and industry participants in the Court of Appeals for the D.C. Circuit and, in February 2016, the implementation of the CPP was stayed by the U.S. Supreme Court. Then, in September 2019, the EPA repealed the CPP and finalized the ACE rule. The ACE rule specified that heat rate improvement measures qualified as the BSER for existing coal-fired power plants, clarified the roles of the EPA and the states in the implementation of the ACE, and revised the NSR permitting program to provide EGUs the opportunity to make efficiency improvements without triggering NSR permit requirements. In January 2021, however, the D.C. Circuit vacated the ACE rule concluding that the EPA's "repeal of the CPP rested critically on a mistaken reading of the CAA." Although the D.C. Circuit ultimately agreed to stay its mandate, such that the CPP remained repealed, in June 2022, the U.S. Supreme Court in West Virginia v. EPA reversed and remanded the D.C. Circuit's decision and found that the EPA had acted outside the bounds of the agency’s authority in the promulgation of the CPP. Notwithstanding the litigation, the 22 Table of Contents CPP and the ACE led to premature retirements and could lead to additional premature retirements of coal-fired generating units and reduce the demand for coal. Congress has not yet adopted legislation to restrict carbon dioxide emissions from existing power plants and has not otherwise expanded the legal authority of the EPA following West Virginia v. EPA, but we cannot predict whether such legislation will be passed in the future or what the potential impacts of such legislation would be. ​ Several rulemakings have been issued under the NSPS that constrain the GHG emissions of fossil-fuel-fired power plants. In October 2015, EPA published its final rule on performance standards for GHG emissions from new, modified, and reconstructed EGUs, which required use of efficient supercritical pulverized coal boilers that use partial post-combustion carbon capture and storage technology and imposed a new emission standard. The October 2015 rule was challenged by several states, industry participants and other parties in the D.C. Circuit and, in April 2017, the Court granted EPA’s motion to hold the litigation in abeyance while EPA reviewed the rule. Then, in December 2018, the EPA issued a proposed rule to replace the October 2015 rule, including revising the BSER for newly constructed coal-fired EGUs. Although the EPA has not taken further action on the December 2018 proposed rule, in May 2023, the EPA published a proposed NSPS rule for GHG emissions from new, modified, and reconstructed fossil fuel-fired EGUs and emissions guidelines for existing fossil fuel-fired EGUs. The final rule is expected in 2024. ​ There are further uncertainties surrounding the potential impacts and costs associated with the reduction of GHG emissions, such as: protests and challenges to the permitting of new fossil-fuel infrastructure by environmental organizations and state regulators; state tort liability; and state adoption of "renewable energy standards" or "renewable portfolio standards," which encourage or require electric utilities to obtain a certain percentage of their electric generation portfolio from renewable resources by a certain date. For example, several states have announced their intent to have renewable energy comprise 100% of their electric generation portfolio and, in December 2021, President Biden issued an executive order setting a goal for a carbon pollution-free electricity sector across the country by 2035. To the extent these requirements or similar requirements that may be enacted or adopted in the future affect our current and prospective customers or those of our mineral interest producers, they may reduce the demand for our coal and the oil & gas produced from the properties in which we hold mineral interests. For more information, see our risk factor titled "We, our customers, or the operators of our oil & gas mineral interests could be subject to litigation related to climate change." ​ In addition, environmental advocacy groups have filed a variety of judicial challenges claiming that the environmental analyses conducted by federal agencies before granting permits and other approvals necessary for certain coal activities do not satisfy the requirements of the NEPA. These groups assert that the environmental analyses in question do not adequately consider the climate change impacts of these particular projects. In April 2022, the CEQ issued a final rule, considered "Phase I" of the Biden Administration’s two-phased approach to modifying the NEPA, revoking some of the modifications made to the NEPA regulations under the previous administration and reincorporating the consideration of direct, indirect, and cumulative effects of major federal actions, including GHG emissions. In July 2023, the CEQ announced a "Phase 2" Notice of Proposed Rulemaking, the "Bipartisan Permitting Reform Implementation Rule," which revises the implementing regulations of the procedural provisions of NEPA and implements the amendments to NEPA included in the June 3, 2023, Fiscal Responsibility Act of 2023. The public comment period for the proposed rule closed in September 2023, and the final rule is expected in the second quarter of 2024. And, in January 2023, the CEQ released guidance, effective upon publication, to assist federal agencies in assessing the GHG emissions and climate change effects of their proposed actions under NEPA. ​ Many states and regions have adopted GHG initiatives and certain governmental bodies have or are considering the imposition of fees or taxes based on the emission of GHG by certain facilities, including coal-fired electric generating facilities. For example, the RGGI calls for the implementation of a cap-and-trade program aimed at reducing carbon dioxide emissions from power plants in participating states. The members of RGGI have established in statutes and/or regulations a carbon dioxide trading program. Similar to RGGI, five western states launched the Western Regional Climate Initiative, although only California, Washington and certain Canadian provinces are currently active participants. We cannot predict what other regional greenhouse gas reduction initiatives may arise in the future. ​ It is possible that future international, federal, and state initiatives to control GHG emissions could result in increased costs associated with fossil-fuel production and consumption, such as costs to install additional controls to reduce carbon dioxide emissions or costs to purchase emissions reduction credits to comply with future emissions trading programs. Such increased costs for fossil-fuel consumption could result in some customers switching to alternative sources of fuel, or otherwise adversely affect our operations and demand for our products, or those of the operators of our mineral interests, which could have a material adverse effect on our business, financial condition, and results of operations. Finally, activists 23 Table of Contents may try to hamper fossil-fuel companies by other means, including pressuring financing and other institutions into restricting access to capital, bonding, and insurance, as well as pursuing tort litigation for various alleged climate-related impacts. For more information, see our Risk Factor titled "Our operations are subject to a series of risks resulting from climate change." ​ Water Discharge ​ The CWA and similar state and local laws and regulations regulate discharges into certain waters, primarily through permitting. Section 404 of the CWA imposes permitting and mitigation requirements associated with the dredging and filling of certain wetlands and streams. The CWA and equivalent state legislation, where such equivalent state legislation exists, affect coal mining operations that impact such wetlands and streams. Although permitting requirements have been tightened in recent years, we believe we have obtained all necessary permits required under CWA Section 404 as it has traditionally been interpreted by the responsible agencies. However, mitigation requirements under existing and possible future "fill" permits may vary considerably. For that reason, the setting of post-mine asset retirement obligation accruals for such mitigation projects is difficult to ascertain with certainty and may increase in the future. For more information about asset retirement obligations, please read "Item 8. Financial Statements and Supplementary Data—Note 18 - Asset Retirement Obligations." Although more stringent permitting requirements may be imposed in the future, we are not able to accurately predict the impact, if any, of such permitting requirements. ​ For us or the operators of the properties in which we hold oil & gas mineral interests to conduct certain activities, an operator may need to obtain a permit for the discharge of fill material from the Corps of Engineers and/or a discharge permit from the state regulatory authority under the state counterpart to the CWA. Our coal mining operations typically require Section 404 permits to authorize activities such as the creation of slurry ponds and stream impoundments. The CWA authorizes the EPA to review Section 404 permits issued by the Corps of Engineers, and in 2009, the EPA began reviewing Section 404 permits issued by the Corps of Engineers for coal mining in Appalachia. Currently, significant uncertainty exists regarding the obtaining of permits under the CWA for coal mining operations in Appalachia due to various initiatives launched by the EPA regarding these permits. ​ The EPA also has statutory "veto" power over a Section 404 permit if the EPA determines, after notice and an opportunity for a public hearing, that the permit will have an "unacceptable adverse effect." This authority has been upheld by the D.C. Circuit. Any future use of the EPA's Section 404 "veto" power could create uncertainty with regard to our continued use of current permits, as well as impose additional time and cost burdens on future operations, potentially adversely affecting our coal revenues. In addition, the EPA initiated a preemptive veto prior to the filing of any actual permit application for a copper and gold mine based on a fictitious mine scenario. The implications of this decision could allow the EPA to bypass the state permitting process and engage in watershed and land use planning. ​ States also have the ability to review the Corps of Engineers’ Section 404 permitting process, pursuant to CWA Section 401, which is also subject to ongoing litigation. In October 2021, the Northern District of California federal court vacated a 2020 rule revising the Section 401 certification process. The Supreme Court stayed this vacatur and, in September 2023, the EPA finalized its Clean Water Act Section 401 Water Quality Certification Improvement Rule, effective on November 27, 2023. While the full extent and impact of these actions is unclear at this time, any disruption in the ability to obtain required permits may result in increased costs and project delays. ​ TMDL regulations under the CWA establish a process to calculate the maximum amount of a pollutant that an impaired waterbody can receive and still meet state water quality standards, and to allocate pollutant loads among the point and non-point pollutant sources discharging into that water body. Likewise, when water quality in a receiving stream is better than required, states are required to conduct an antidegradation review before approving discharge permits. The adoption of new TMDL-related allocations or any changes to antidegradation policies for streams near our coal mines could require more costly water treatment and could adversely affect our coal production. ​ Considerable legal uncertainty exists surrounding the standard for what constitutes jurisdictional waters and wetlands subject to the protections and requirements of the CWA. Rulemakings to establish the extent of such jurisdiction were finalized in 2015 and 2020, respectively, and both rulemakings have been subject to substantial litigation. Although the EPA and Corps of Engineers did not seek to vacate the 2020 rule on an interim basis, two federal district courts in Arizona and New Mexico vacated the 2020 rule in decisions announced during the third quarter of 2021. In January 2023, the EPA and Corps of Engineers published a final revised definition of WOTUS founded upon a pre-2015 definition, including updates to incorporate existing Supreme Court decisions. However, continued uncertainty remains as to the government's 24 Table of Contents jurisdictional reach as the rule is likely to be subject to legal challenge. Judicial developments further add to this uncertainty. In October 2022, the Supreme Court heard oral arguments in Sackett v. EPA regarding the scope and authority of the CWA and the definition of WOTUS and in May 2023, issued a ruling invalidating certain parts of the January 2023 rule, and further limiting the federal government’s jurisdiction over wetlands and tributaries. A revised WOTUS rule was issued in September 2023. Due to the injunction in certain states, however, the implementation of the September 2023 rule currently varies by state. ​ Hazardous Substances and Wastes ​ The CERCLA, otherwise known as the "Superfund" law, and analogous state laws, impose liability, without regard to fault or the legality of the original conduct on certain classes of persons that are considered to have contributed to the release of a "hazardous substance" into the environment. These persons include the owner or operator of the site where the release occurred and companies that disposed of or arranged for the disposal of the hazardous substances found at the site. Persons who are or were responsible for the release of hazardous substances may be subject to joint and several liability under CERCLA for the costs of cleaning up releases of hazardous substances and natural resource damages. Some products used in coal mining operations generate waste containing hazardous substances. We are currently unaware of any material liability associated with the release or disposal of hazardous substances from our past or present mine sites. ​ The RCRA and analogous state laws impose requirements for the generation, transportation, treatment, storage, disposal, and cleanup of hazardous and non-hazardous wastes. Many mining wastes are excluded from the regulatory definition of hazardous wastes, and coal mining operations covered by SMCRA permits are by statute exempted from RCRA permitting. Similarly, most wastes associated with the exploration, development, and production of oil & gas are exempt from regulation as hazardous wastes under RCRA, though these wastes typically constitute "solid wastes" that are subject to less stringent non-hazardous waste requirements. However, it is possible that RCRA could be amended or the EPA or state environmental agencies could adopt policies to require such wastes to become subject to more stringent storage, handling, treatment, or disposal requirements, which could impose significant additional costs on the operators of the properties in which we own oil & gas mineral interests. RCRA also allows the EPA to require corrective action at sites where there is a release of hazardous substances. In addition, each state has its own laws regarding the proper management and disposal of waste material. While these laws impose ongoing compliance obligations, such costs are not believed to have a material impact on our operations. ​ RCRA impacts the coal industry in particular because it regulates the disposal of certain CCB. On April 17, 2015, the EPA finalized regulations under RCRA for the disposal of CCB. Under the finalized regulations, CCB is regulated as "non-hazardous" waste and avoids the stricter, more costly, regulations under RCRA's "hazardous" waste rules. While the classification of CCB as a hazardous waste would have led to more stringent restrictions and higher costs, this regulation may still increase our customers' operating costs and potentially reduce their ability to purchase coal. The CCB rule was subject to legal challenge and ultimately remanded to the EPA. On August 28, 2020, the EPA published a final revised rule mandating the closure of unlined impoundments, with deadlines to initiate closure between 2021 and 2028, depending on site-specific circumstances. Certain provisions of the revised CCB rule were vacated by the D.C. Circuit in 2018. The EPA proposed a coal ash rule in May 2023 and the final rule is expected in April 2024. Meanwhile, on January 25, 2022, the EPA published determinations for 9 of 57 CCB facilities that sought approval to continue disposal of CCB and non-CCB waste streams until 2023, as opposed to the initial 2021 deadline for unlined impoundments prescribed by the current rule. While the EPA issued one conditional approval, the EPA required the remaining facilities to cease receipt of waste within 135 days of completion of public comment, or around July 2022. And, in January 2023, the EPA issued six proposed determinations to deny facilities' requests to continue disposal into unlined surface impoundments. The current determinations, future determinations of the same nature, or similar actions in expected future rulemakings could lead to accelerated, abrupt, or unplanned suspension of coal-fired boilers. The combined effect of the CCB rules and the ELG regulations (discussed below) has compelled power generating companies to close existing ash ponds and may force the closure of certain existing coal burning power plants that cannot comply with the new standards. Such retirements may adversely affect the demand for our coal. ​ On November 3, 2015, the EPA published the final rule ELG, revising the regulations for the Steam Electric Power Generating category which became effective on January 4, 2016. The rule sets the first federal limits on the levels of toxic metals in wastewater that can be discharged from power plants, based on technological improvements in the steam electric power industry over the last three decades. The combined effect of the CCB and ELG regulations has forced power generating companies to close existing ash ponds and will likely force the closure of certain older existing coal-burning power plants that cannot comply with the new standards. In November 2019, the EPA proposed revisions to the 2015 ELG 25 Table of Contents rule and announced proposed changes to regulations for the disposal of coal ash in order to reduce compliance costs. In October 2020, EPA published a final rule. In August 2021, EPA initiated supplemental rulemaking indicating that it intended to strengthen certain discharge limits. In March 2023, the EPA proposed a rule to establish more stringent ELG regulations and the final rule is expected in April 2024. It is unclear what impact these regulations will have on the market for our products. ​ Endangered Species Act ​ The federal ESA and counterpart state legislation protect species threatened with possible extinction. The USFWS works closely with the OSM and state regulatory agencies to ensure that species subject to the ESA are protected from potential impacts from mining-related and oil & gas exploration and production activities. In October 2021, the Biden Administration proposed the rollback of new rules promulgated under the Trump Administration and published an advanced notice of proposed rulemaking to codify a general prohibition on incidental take while establishing a process to regulate or permit exceptions to such a prohibition. In February 2023, the USFWS published a proposed rule that revised the requirements for an incidental take permit application. A final rule is scheduled for release in the first quarter of 2024. Additionally, in June 2022, the USFWS and the National Marine Fisheries Service published a final rule rescinding the 2020 regulatory definition of "habitat." If the USFWS were to designate species indigenous to the areas in which we operate as threatened or endangered or to redesignate a species from threatened to endangered, we or the operators of the properties in which we hold oil & gas mineral interests could be subject to additional regulatory and permitting requirements, which in turn could increase operating costs or adversely affect our revenues. ​ Other Environmental, Health, and Safety Regulations ​ In addition to the laws and regulations described above, we are subject to regulations regarding underground and above-ground storage tanks in which we may store petroleum or other substances. Some monitoring equipment that we use is subject to licensing under the Federal Atomic Energy Act. Water supply wells located on our properties are subject to federal, state, and local regulations. In addition, our use of explosives is subject to the Federal Safe Explosives Act. We are also required to comply with the Federal Safe Drinking Water Act, the Toxic Substance Control Act, and the Emergency Planning and Community Right-to-Know Act. The costs of compliance with these regulations should not have a material adverse effect on our business, financial condition, or results of operations. ​ Human Capital ​ To conduct our operations, as of December 31, 2023, we employed 3,595 full-time employees, including 3,038 employees involved in active coal mining operations, 408 employees in other operations, and 193 corporate employees. In 2023 we reviewed the work duties of our employees and reclassified 68 of our technical services employees from corporate employees to employees involved in other operations. Our workforce is entirely union-free. Our typical employee has approximately six years of experience with the Partnership and more than 40% of all employees remain employed for more than five years. ​ To attract and retain the most qualified personnel across all functions of our business we offer competitive compensation packages. In making decisions regarding employee compensation, we review current compensation levels for each position within other companies in the coal industry and other peers and use our discretion to determine an appropriate total compensation package, which generally includes some combination of base salary, incentive compensation, health and welfare benefits and participation in our profit sharing and savings plan. Depending on the position and employer, incentive compensation bonuses can be based on production and safety goals at a specific coal operation or broader performance goals across the Partnership, among other factors. We intend for each employee's total compensation to be competitive in the marketplace. ​ Workplace safety is fundamental to our culture. By providing a work environment that rewards safety and encourages employee participation in the safety process, we have a demonstrated history as a leader in safety performance in the coal mining industry. We are focused on improving employee safety through regular training and continuous monitoring of our progress through various industry-standard metrics. In addition, we collected approximately 13,800 respirable dust samples from the mining environment where our miners regularly work and travel. The average concentration of those samples was 56% below the regulatory standard. We are also regularly inspected by MSHA. For more information about citations or orders for violations of standards under the FMSHA, as amended by the MINER Act, please see our Exhibit 95.1 to this Annual Report on Form 10-K. 26 Table of Contents ​ We are focused on the health of our employees. In addition to providing medical, dental, and vision benefits for our employees, we also provide on-site medical clinics to provide medical services to our employees and their families. Furthermore, at each of our coal operations and corporate offices, we provide a human resource representative to assist employees with various human resource matters. The Partnership also administers our medical plan, which allows us to control costs and work directly on behalf of our employees with healthcare providers. To date, we have been able to continue providing health and welfare benefits with no out-of-pocket premiums for our employees and 100% coverage with direct contract providers. ​ 27 Table of Contents ITEM 1A. RISK FACTORS ​ Summary Risk Factors ​ Our business is subject to a number of risks, including risks that could prevent us from achieving our business objectives or could adversely affect our business, financial condition, results of operations, cash flows, and prospects. These risks are discussed more fully below and include but are not limited to risks related to: ​ Risks Inherent in an Investment in Us ● Cash distributions are not guaranteed ● Ownership of limited partner interests could be diluted ● Sales of our common units could cause decline in the market price of our common units ● Increase in interest rates could cause decline in the market price of our common units ● The credit risk of our general partner could adversely impact us ● Our unitholders do not elect the general partner ● The control of our general partner may be transferred to a third party ● Unitholders may be required to sell their units to our general partner ● Cost reimbursements due to our general partner could be substantial ● Your liability as a limited partner may not be limited under certain circumstances ● Our general partner's fiduciary duties are limited ● Our general partner has discretion in determining the level of cash reserves ● Our general partner has potential conflicts of interest ● Some executive officers and directors face potential conflicts of interest ● ESG scores could adversely impact our securities ​ Risks Related to Our Business ● Declining global economic conditions could adversely impact us ● Material adverse effects on our financial condition as a result of future pandemic outbreaks could adversely impact us ● Financing may not be available to us on favorable terms or at all ● Our indebtedness could adversely impact us ● We depend upon the leadership of key personnel ● Legal proceedings could adversely impact us ● Our customers may not honor their contracts or may not enter into new contracts for our products ● Some of our contracts may be renegotiated or terminated ● We depend upon a few customers for significant portions of our revenues ● The credit risk of our customers could adversely impact us ● Cyber or terrorist attacks could adversely impact us ● Establishment of labor unions at our operations could adversely affect our profitability ​ Risks Related to Our Industries ● Changes in coal prices and/or oil & gas prices could impact our results of operations ● Competition within the coal industry could adversely affect our ability to sell coal ● Changes in taxes or tariffs and trade measures could adversely impact us ● Global geopolitical tensions which have caused, and may cause in the future, significant market disputes that may lead to increased volatility in the price of commodities ● Changes in consumption patterns by utilities could affect our ability to sell coal and/or impact the price of our natural gas ● Tort claims based on climate change ● Litigation resulting from disputes with customers could result in costs and liabilities ● Unanticipated mine operating conditions could affect our profitability ● Inability to obtain and renew permits necessary for operations could limit our ability to continue or expand our operations ● Fluctuations in transportation costs and availability could reduce demand for our products ● Unexpected increases in raw material costs could impact the profitability of our operations 28 Table of Contents ● The ability to recruit, hire and retain skilled labor could impact the profitability of our operations ● Disruptions in supply chains could impact the profitability of our operations ● Inflationary pressures could impact the profitability of our operations ● Unavailability of economic coal mineral reserves and resources could limit our ability to continue or expand our operations ● Estimates of our coal mineral reserves and resources could be inaccurate and could result in decreased profitability ● Coal mining in certain areas could be difficult and involve regulatory constraints which could impact our operations ● Extensive environmental laws and regulations could reduce demand for coal as a fuel source ● Legislative and regulatory compliance is costly ● Legislative and regulatory compliance could impact our business ● Legislative and regulatory initiatives relating to hydraulic fracturing could impact our mineral interests ● Legislative and regulatory initiatives relating to seismic activity could impact our business ● Legislative and regulatory initiatives relating to climate change could impact demand for our products ● Mine facilities may be located in a leased portion of the surface properties which introduces a risk of disruption to our operations ● Inability to acquire or failure to maintain surety bonds could limit our ability to continue or expand our operations ● Dependency on unaffiliated operators to explore and drill on our oil & gas properties limits our ability to control the timing and quantity of production ● Delays in royalty payments and optional royalty payments could impact our business ● Suspension of the right to receive royalty payments could impact our business ● Estimates of our oil & gas reserves could be inaccurate and could result in decreased profitability ● Uncertainties involved in drilling for and producing oil & gas could impact our business ● Availability of transportation and facilities for the products could impact our business ● Lack of hedging arrangements exposes us to the impact of commodity prices ● Expansions and acquisitions have inherent risks that could adversely impact us ● Integration of expansions or acquisitions has inherent risks that could adversely impact us ● Inability to obtain commercial insurance at acceptable rates could have a negative impact on our business ​ Tax Risks to Our Common Unitholders ● Our tax treatment depends on our status as a partnership for U.S. federal income tax purposes, and not being subject to a material amount of entity-level taxation. Our cash available for distribution to unitholders may be substantially reduced if we become subject to entity-level taxation as a result of the IRS treating us as a corporation or legislative, judicial, or administrative changes, and may also be reduced by any audit adjustments if imposed directly on the Partnership. ● Even if unitholders do not receive any cash distributions from us, unitholders will be required to pay taxes on their share of our taxable income. A unitholder's share of our taxable income may be increased as a result of the IRS successfully contesting any of the federal income tax positions we take. ● Tax gain or loss on the disposition of our units could be more than expected and create tax liabilities for our unitholders ● Limitation on unitholders' ability to deduct interest expense incurred by us could create tax liabilities for our unitholders ● Tax Exempt entities and non-U.S. unitholders face unique tax issues from owning our common units that may result in adverse tax consequences for them ● IRS challenging our allocation of depreciation and amortization deductions could cause adverse tax consequences ● IRS challenging methods of prorating items of income, gain, loss, and deduction could cause adverse tax consequences ● Unitholders with units subject to securities loans could face adverse tax consequences ● Certain U.S. federal income tax deductions currently available with respect to coal mining and production may be eliminated as a result of future legislation ● Unitholders could be subject to state and local taxes and income tax return filing due to their status as a unitholder ​ 29 Table of Contents Risks Inherent in an Investment in Us ​ Cash distributions to unitholders are not guaranteed. ​ The payment and amount of any future distribution will be subject to the sole discretion of the Board of Directors and will depend upon many factors, including our financial condition and prospects, our capital requirements and access to financing, covenants associated with our debt obligations, and other factors that our Board of Directors may deem relevant, and there can be no assurance that we will pay a distribution in the future. The amount of cash we can distribute to holders of our common units or other partnership securities each quarter principally depends on the amount of cash we generate from our operations, which fluctuates from quarter to quarter. In addition, the actual amount of cash available for distribution may depend on other factors, including capital allocation decisions, financing availability, restrictions in debt agreements, and the amount of cash reserves, if any, established by the general partner, in its discretion, for the proper conduct of our business. ​ Furthermore, since the amount of cash we have available for distribution is not solely a function of profitability, which will be affected by non-cash items, we may make cash distributions during periods when we record net losses and may be unable to make cash distributions during periods when we record net income. Please read "—Risks Related to our Business" for a discussion of further risks affecting our ability to generate available cash. ​ We may issue an unlimited number of limited partner interests, on terms and conditions established by our general partner, without the consent of our unitholders, which will dilute your ownership interest in us and could increase the risk that we will not have sufficient available cash to make distributions. ​ The issuance by us of additional common units or other equity securities of equal or senior rank will have the following effects: ​ ● our unitholders ' proportionate ownership interest in us will decrease; ● the amount of cash available for distribution on each unit could decrease; ● the relative voting strength of each previously outstanding unit could be diminished; ● the ratio of taxable income to distributions could increase; and ● the market price of our common units could decline. ​ The market price of our common units could be adversely affected by sales of substantial amounts of our common units in the public markets, including sales by our existing unitholders. ​ The sale or disposition of a substantial number of our common units by our existing unitholders in the public markets could have a material adverse effect on the price of our common units or could impair our ability to obtain capital through an offering of equity securities. We do not know whether any such sales would be made in the public market or private placements, nor do we know what impact such potential or actual sales would have on our unit price in the future. ​ An increase in interest rates could cause the market price of our common units to decline. ​ Like all equity investments, an investment in our common units is subject to certain risks. In exchange for accepting these risks, investors may expect to receive a higher rate of return than would otherwise be obtainable from lower-risk investments. Accordingly, as interest rates rise, the ability of investors to obtain higher risk-adjusted rates of return by purchasing government-backed debt securities could cause a corresponding decline in demand for riskier investments generally, including yield-based equity investments such as publicly traded limited partnership interests. Reduced demand for our common units resulting from investors seeking other more favorable investment opportunities could cause the trading price of our common units to decline. ​ The credit and risk profile of our general partner and its owners could adversely affect our credit ratings and profile. ​ The credit and risk profile of our general partner or its owners may be factors in credit evaluations of us as a master limited partnership. This is because our general partner can exercise significant influence or control over our business activities, including our cash distribution policy, acquisition strategy, and business risk profile. ​ 30 Table of Contents Our unitholders do not elect our general partner or vote on our general partner's officers or directors. ​ Unlike the holders of common stock in a corporation, our unitholders have only limited voting rights on matters affecting our business and, therefore, limited ability to influence management's decisions regarding our business. Unitholders did not elect our general partner and will have no right to elect our general partner on annual or other continuing bases. If our unitholders are dissatisfied with the performance of our general partner, they will have little ability to remove our general partner. Our general partner may not be removed except upon the vote of the holders of at least 66.7% of our outstanding units. ​ Our unitholders' voting rights are also restricted by a provision in our partnership agreement that provides that any units held by a person that owns 20.0% or more of any class of units then outstanding, other than our general partner and its affiliates, cannot be voted on any matter. ​ The control of our general partner may be transferred to a third party without unitholder consent. ​ Our general partner may transfer its general partner interest in us to a third party in a merger or a sale of its equity securities without the consent of our unitholders. Furthermore, there is no restriction in the partnership agreement on the ability of the members of our general partner to sell or transfer all or part of their ownership interest in our general partner to a third party. The new owner or owners of our general partner would then be in a position to replace the directors and officers of our general partner and control the decisions made and actions taken by the Board of Directors and officers. ​ Unitholders may be required to sell their units to our general partner at an undesirable time or price. ​ If at any time less than 20.0% of our outstanding common units are held by persons other than our general partner and its affiliates, our general partner will have the right to acquire all, but not less than all, of those units at a price no less than their then-current market price. As a consequence, a unitholder may be required to sell his common units at an undesirable time or price. Our general partner may assign this purchase right to any of its affiliates or us. ​ Cost reimbursements due to our general partner could be substantial and could reduce our ability to pay distributions to unitholders. ​ Before making any distributions to our unitholders, we will reimburse our general partner and its affiliates for all expenses they have incurred on our behalf. The reimbursement of these expenses and the payment of these fees could adversely affect our ability to make distributions to the unitholders. Our general partner has sole discretion to determine the amount of these expenses and fees. For additional information, please see "Item 13. Certain Relationships and Related Transactions, and Director Independence—Related-Party Transactions— Administrative Services. " ​ Your liability as a limited partner may not be limited, and our unitholders could have to repay distributions or make additional contributions to us under certain circumstances. ​ As a limited partner in a partnership organized under Delaware law, you could be held liable for our obligations to the same extent as a general partner if you participate in the "control" of our business. Our general partner generally has unlimited liability for the obligations of the partnership, except for those contractual obligations of the partnership that are expressly made without recourse to our general partner. Additionally, the limitations on the liability of holders of limited partner interests for the obligations of a limited partnership have not been established in many jurisdictions. ​ Under certain circumstances, our unitholders could have to repay amounts wrongfully distributed to them. Under Delaware law, we may not make a distribution to our unitholders if the distribution would cause our liabilities to exceed the fair value of our assets. Delaware law provides that for three years from the date of the impermissible distribution, partners who received the distribution and who knew at the time of the distribution that it violated Delaware law will be liable to the partnership for the distribution amount. Liabilities to partners on account of their partnership interest and liabilities that are non-recourse to the partnership are not counted for purposes of determining whether a distribution is permitted. ​ 31 Table of Contents Our partnership agreement limits our general partner ' s fiduciary duties to our unitholders and restricts the remedies available to unitholders for actions taken by our general partner that may otherwise constitute breaches of fiduciary duty. ​ Our partnership agreement contains provisions that waive or consent to conduct by our general partner and its affiliates and which reduce the obligations to which our general partner would otherwise be held by state-law fiduciary duty standards. The following is a summary of the material restrictions contained in our partnership agreement on the fiduciary duties owed by our general partner to the limited partners. Our partnership agreement: ​ ● permits our general partner to make many decisions in its "sole discretion." This entitles our general partner to consider only the interests and factors that it desires, and it has no duty or obligation to give any consideration to any interest of, or factors affecting us, our affiliates, or any limited partner; ● provides that our general partner is entitled to make other decisions in its "reasonable discretion"; ● generally provides that affiliated transactions and resolutions of conflicts of interest not involving a required vote of unitholders must be "fair and reasonable" to us and that, in determining whether a transaction or resolution is "fair and reasonable," our general partner may consider the interests of all parties involved, including its own. Unless our general partner has acted in bad faith, the action taken by our general partner shall not constitute a breach of its fiduciary duty; and ● provides that our general partner and our officers and directors will not be liable for monetary damages to us, our limited partners, or assignees for errors of judgment or any acts or omissions if our general partner and those other persons acted in good faith. ​ All limited partners are bound by the provisions in the partnership agreement, including the provisions discussed above. ​ Our general partner's discretion in determining the level of cash reserves may adversely affect our ability to make cash distributions to our unitholders. ​ Our partnership agreement requires our general partner to deduct from available cash reserves that in its reasonable discretion are necessary for the proper conduct of our business, to comply with applicable law or agreements to which we are a party, or to provide funds for future distributions to partners. These cash reserves will affect the amount of cash available for distribution to unitholders. ​ Our general partner has conflicts of interest and limited fiduciary responsibilities, which may permit our general partner to favor its interests to the detriment of our unitholders. ​ Conflicts of interest could arise in the future as a result of relationships between our general partner and its affiliates, on the one hand, and us, on the other hand. As a result of these conflicts, our general partner may favor its interests and those of its affiliates over the interests of our unitholders. The nature of these conflicts includes the following considerations: ​ ● Remedies available to our unitholders for actions that, without the limitations, could constitute breaches of fiduciary duty are limited. Unitholders are deemed to have consented to some actions and conflicts of interest that could otherwise be deemed a breach of fiduciary or other duties under applicable state law. ● Our general partner is allowed to take into account the interests of parties in addition to us in resolving conflicts of interest, thereby limiting its fiduciary duties to our unitholders. ● Our general partner's affiliates are not prohibited from engaging in other businesses or activities, including those in direct competition with us, except as provided in the omnibus agreement (please see "Item 13. Certain Relationships and Related Transactions, and Director Independence—Omnibus Agreement"). ● Our general partner determines the amount and timing of our asset purchases and sales, capital expenditures, borrowings, and reserves, each of which can affect the amount of cash that is distributed to unitholders. ● Our general partner determines whether to issue additional units or other equity securities in us. ● Our general partner determines which costs are reimbursable by us. ● Our general partner controls the enforcement of obligations owed to us by it. ● Our general partner decides whether to retain separate counsel, accountants, or others to perform services for us. 32 Table of Contents ● Our general partner is not restricted from causing us to pay it or its affiliates for any services rendered on terms that are fair and reasonable to us or from entering into additional contractual arrangements with any of these entities on our behalf. ● In some instances, our general partner may direct us to borrow funds to permit the payment of distributions. ​ Some of our executive officers and directors face potential conflicts of interest in managing our business. ​ Certain of our executive officers and directors are also officers and/or directors of AGP. These relationships could create conflicts of interest regarding corporate opportunities and other matters. The resolution of any such conflicts may not always be in our or our unitholders' best interests. These officers and directors face potential conflicts regarding the allocation of their time, which could adversely affect our business, results of operations, and financial condition. ​ Increasing attention to ESG matters may negatively impact our business, financial results, and unit price. ​ Companies across all industries, including companies in fossil-fuel industries, are facing increased scrutiny from stakeholders related to their ESG practices. Companies that do not adapt or comply with evolving investor or stakeholder expectations and standards, or are perceived to have not responded appropriately to ESG issues, regardless of any legal requirement to do so, may suffer reputational damage and the business, financial condition, and valuation of such companies could be materially and adversely affected. Several advocacy groups, both domestically and internationally, have campaigned for governmental and private action to promote change at public companies related to ESG matters, including through the investment and voting practices of investment advisers, public pension funds, universities, and other members of the investing community. These activities include increasing attention to and demands for action related to climate change, promoting the use of substitutes to fossil-fuel products, encouraging the divestment of fossil-fuel equities, and pressuring lenders to limit funding to companies engaged in the extraction of fossil-fuel reserves. These activities could increase costs, reduce demand for our coal and hydrocarbon products, reduce our profits, increase the potential for investigations and litigation, impair our brand, limit our choices for lenders, insurance providers and business partners, and have negative impacts on our unit price and access to capital markets. ​ In addition, certain organizations that provide corporate governance and other corporate risk information to investors and unitholders have developed scores and ratings to evaluate companies and investment funds based on ESG or "sustainability" metrics. Currently, there are no universal standards for such scores or ratings, but consideration of sustainability evaluations is becoming more broadly accepted by investors. Indeed, many investment funds focus on positive ESG business practices and sustainability scores when making investments, whereas other funds may use certain ESG criteria to "screen" certain sectors, such as coal or fossil fuels more generally, out of their investments. In addition, investors, particularly institutional investors, use these scores to benchmark companies against their peers and if a company is perceived as lagging, these investors may engage with companies to require improved ESG disclosure or performance or sell their interests in the company, particularly if its ESG performance does not improve. Moreover, certain members of the broader investment community may consider a company's sustainability score as a reputational or other factor in making an investment decision. Companies in the energy industry, and in particular those focused on coal, natural gas, or oil extraction, often do not score as well under ESG assessments compared to companies in other industries. Consequently, a low ESG or sustainability score could result in our securities, both debt and equity, being excluded from the portfolios of certain investment funds and investors, restricting our access to capital to fund our continuing operations and growth opportunities. Additionally, to the extent ESG matters negatively impact our reputation, we may not be able to compete as effectively to recruit or retain employees, which may adversely affect our operations. ​ Public statements with respect to ESG matters, such as emission reduction goals, other environmental targets, or other commitments addressing certain social issues, are becoming increasingly subject to heightened scrutiny from public and governmental authorities related to the risk of potential "greenwashing," i.e., misleading information or false claims overstating potential ESG benefits. For example, in March 2021, the SEC established the Climate and ESG Task Force in the Division of Enforcement to identify and address potential ESG-related misconduct, including greenwashing. Certain non-governmental organizations and other private actors have also filed lawsuits under various securities and consumer protection laws alleging that certain ESG-statements, emission reduction claims, approaches to accounting for GHG emissions reductions, or other ESG-related goals, or standards were misleading, false, or otherwise deceptive. As a result, we may face increased litigation risks from private parties and governmental authorities related to our ESG efforts. In addition, any alleged claims of greenwashing against us or others in our industry may lead to further negative sentiment and diversion of investments. Additionally, we could face increasing costs as we attempt to comply with and navigate further ESG-related focus and scrutiny. 33 Table of Contents ​ Risks Related to our Business ​ Global economic conditions or economic conditions in any of the industries in which our customers operate as well as sustained uncertainty in financial markets could have material adverse impacts on our business and financial condition that we currently cannot predict. ​ Weakness in global economic conditions or economic conditions in any of the industries we serve or in the financial markets could materially adversely affect our business and financial condition. For example: ​ ● the demand for electricity in the United States and globally could decline if economic conditions deteriorate, which could negatively impact the revenues, margins, and profitability of our business; ● any inability of our customers to raise capital could adversely affect their ability to honor their obligations to us; and ● our future ability to access the capital markets could be restricted as a result of future economic conditions, which could materially impact our ability to grow our business, including the development of our coal mineral reserves and resources. ​ We face various risks related to pandemics and similar outbreaks, which have had and may in the future have material adverse effects on our business, financial position, results of operations, and/or cash flows. ​ Pandemics, outbreaks or other public health events that are outside of our control could significantly disrupt our operations and adversely affect our financial condition. The global or national outbreak of an illness or other communicable disease, or any other public health crisis, such as COVID-19, may cause disruptions to our business and operations, which may include (i) shortages of employees, (ii) unavailability of contractors or subcontractors, (iii) interruption of supplies from third parties upon which we rely, (iv) restrictions recommended or imposed by government and health authorities, including quarantines, to address an outbreak and (v) restrictions that we and our contractors, subcontractors and our customers impose, including facility shutdowns, to ensure the safety of employees. ​ The extent to which COVID-19 or another future pandemic may adversely impact our results of operations, cash flows and financial condition depends on future developments, which are highly uncertain and unpredictable. ​ Growing our business could require significant amounts of financing that may not be available to us on acceptable terms, or at all. ​ We plan to fund capital expenditures for our growth initiatives with existing cash balances, future cash flows from operations, borrowings under revolving credit and securitization facilities, and cash provided from the issuance of debt or equity. At times, weakness in the energy sector in general and coal, in particular, has significantly impacted access to the debt and equity capital markets. Accordingly, our funding plans could be negatively impacted by constraints in the capital markets as well as numerous other factors, including higher than anticipated capital expenditures or lower than expected cash flow from operations. In addition, we could be unable to refinance our current debt obligations when they expire or obtain adequate funding prior to expiry because our lending counterparties may be unwilling or unable to meet our funding needs. Furthermore, additional growth projects and expansion opportunities could develop in the future that could also require significant amounts of financing that may not be available to us on acceptable terms or in the amounts we expect, or at all. ​ Various factors could adversely impact the debt and equity capital markets as well as our credit ratings or our ability to remain in compliance with the financial covenants under our then-current debt agreements, which in turn could have a material adverse effect on our financial condition, results of operations, and cash flows. If we are unable to finance our growth initiatives as expected, we could be required to seek alternative financing, the terms of which may not be attractive to us, or to revise or cancel our plans. ​ 34 Table of Contents Our indebtedness could limit our ability to borrow additional funds, make distributions to unitholders, or capitalize on business opportunities. ​ We had long-term indebtedness of $347.6 million as of December 31, 2023. Our leverage may: ​ ● adversely affect our ability to finance future operations and capital needs; ● limit our ability to pursue acquisitions and other business opportunities; ● make our results of operations more susceptible to adverse economic or operating conditions; and ● make it more difficult to self-insure for our workers' compensation obligations. ​ In addition, we have unused borrowing capacity under our revolving credit facility. Future borrowings, under our credit facilities or otherwise, could increase our leverage. ​ Our payments of principal and interest on any indebtedness will reduce the cash available for distribution on our units. We will be prohibited from making cash distributions: ​ ● during an event of default under any of our indebtedness; or ● if after such distribution, we fail to meet a coverage test based on the ratio of our consolidated cash flow to our consolidated fixed charges. ​ Various limitations in our debt agreements may reduce our ability to incur additional indebtedness, engage in some transactions, and capitalize on business opportunities. Any subsequent refinancing of our current indebtedness or any new indebtedness could have similar or greater restrictions. Please see "Item 8. Financial Statements and Supplementary Data—Note 6 – Long-Term Debt" for further discussion. ​ We depend on the leadership and involvement of Joseph W. Craft III and other key personnel for the success of our business. ​ We depend on the leadership and involvement of Mr. Craft. Mr. Craft has been integral to our success, due in part to his ability to identify and develop internal growth projects and accretive acquisitions, make strategic decisions, and attract and retain key personnel. The loss of his leadership and involvement or the services of any members of our senior management team could have a material adverse effect on our business, financial condition, and results of operations. ​ We and our subsidiaries are subject to various legal proceedings, which could have a material adverse effect on our business. ​ We are party to a number of legal proceedings incident to our normal business activities. There is the potential that an individual matter or the aggregation of multiple matters could have an adverse effect on our cash flows, results of operations, or financial position. Please see "Item 3. Legal Proceedings" and "Item 8. Financial Statements and Supplementary Data—Note 21 – Commitments and Contingencies" for further discussion. ​ The stability and profitability of our operations could be adversely affected if our customers do not honor existing contracts or do not extend existing or enter into new long-term contracts for coal. ​ In 2023, we sold approximately 93.4% of our coal sales tonnage under contracts having a term greater than one year, which we refer to as long-term sales contracts. These contracts have historically provided a relatively secure market for the production committed under the terms of the contracts. From time to time industry conditions could make it more difficult for us to enter into long-term sales contracts with our electric utility customers, and if supply exceeds demand in the coal industry, electric utilities may become less willing to lock in price or quantity commitments for an extended period of time. Accordingly, we may not be able to continue to obtain long-term sales contracts with reliable customers as existing contracts expire, which could subject a portion of our revenue stream to the increased volatility of the spot market. ​ Some of our long-term sales contracts contain provisions allowing for the renegotiation of prices and, in some instances, the termination of the contract or the suspension of purchases by customers. ​ Some of our long-term sales contracts contain provisions that allow the purchase price to be renegotiated at periodic intervals. These price reopener provisions may automatically set a new price based on the prevailing market price or, in 35 Table of Contents some instances, require the parties to the contract to agree on a new price. Any adjustment or renegotiation leading to a significantly lower contract price could adversely affect our operating profit margins. Accordingly, long-term sales contracts may provide only limited protection during adverse market conditions. In some circumstances, the failure of the parties to agree on a price under a reopener provision can also lead to the early termination of a contract. ​ Several of our long-term sales contracts also contain provisions that allow the customer to suspend or terminate performance under the contract upon the occurrence or continuation of certain events that are beyond the customer's reasonable control. Such events could include labor disputes, mechanical malfunctions, and changes in government regulations, including changes in environmental regulations rendering the use of our coal inconsistent with the customer's environmental compliance strategies. Additionally, most of our long-term sales contracts contain provisions requiring us to deliver coal within stated ranges for specific coal characteristics. Failure to meet these specifications can result in economic penalties, rejection or suspension of shipments, or termination of the contracts. In the event of early termination of any of our long-term sales contracts, if we are unable to enter into new contracts on similar terms, our business, financial condition, and results of operations could be adversely affected. ​ We depend on a few customers for a significant portion of our revenues, and the loss of one or more significant customers could affect our ability to maintain the sales volume and price of the coal we produce. ​ In 2023, we derived more than 10% of our total revenues from each of American Electric Power and Tennessee Valley Authority. If we were to lose this or any of our significant customers without finding replacement customers willing to purchase an equivalent amount of coal on similar terms, or if these customers were to decrease the amounts of coal purchased or change the terms, including pricing terms, on which they buy coal from us, it could have a material adverse effect on our business, financial condition, and results of operations. ​ Our ability to collect payments from our customers could be impaired if their creditworthiness declines or if they fail to honor their contracts with us. ​ Our ability to receive payment for coal sold and delivered depends on the continued creditworthiness of our customers. If the creditworthiness of our customers declines significantly, our business could be adversely affected. In addition, if a customer refuses to accept shipments of our coal for which they have an existing contractual obligation, our revenues will decrease and we may have to reduce production at our mines until our customer's contractual obligations are honored. ​ Terrorist attacks or cyber incidents could result in information theft, data corruption, operational disruption, and/or financial loss. ​ Like most companies, we have become increasingly dependent upon digital technologies, including information systems, infrastructure, and cloud applications and services, to operate our businesses, process and record financial and operating data, communicate with our business partners, analyze mine and mining information, and estimate quantities of reserves and resources, as well as other activities related to our businesses. Strategic targets, such as energy-related assets, could be at greater risk of future terrorist or cyber-attacks than other targets in the United States. Deliberate attacks on, or security breaches in, our systems or infrastructure, or the systems or infrastructure of third parties could lead to corruption or loss of our proprietary data and potentially sensitive data, delays in production or delivery, difficulty in completing and settling transactions, misdirected wire transfers, challenges in maintaining our books and records, environmental damage, communication interruptions, other operational disruptions, and third-party liability. Our insurance may not protect us against such occurrences. Consequently, it is possible that any of these occurrences, or a combination of them, could have a material adverse effect on our business, financial condition, results of operations, cash flows and reputation. Further, as cyber incidents continue to evolve, we could be required to expend additional resources to continue to modify or enhance our protective measures or to investigate and remediate any vulnerability to cyber incidents. ​ Although none of our employees are members of unions, our workforce may not remain union-free in the future. ​ None of our employees are represented under collective bargaining agreements. However, our workforce may not remain union-free in the future, and legislative, regulatory, or other governmental action could make it more difficult to remain union-free. If some or all of our currently union-free operations were to become unionized, it could adversely affect our productivity and increase the risk of work stoppages at our mining complexes. In addition, even if we remain union-free, our operations could still be adversely affected by work stoppages at unionized companies, particularly if union workers were to orchestrate boycotts against our operations. 36 Table of Contents ​ Risks Related to Our Industries ​ Prices for oil & gas, as well as coal, are volatile and can fluctuate widely based on a number of factors beyond our control. An extended decline in the prices of such commodities could negatively impact our results of operations. ​ Our results of operations are primarily dependent upon the prices of oil & gas and coal, as well as our ability to improve productivity and control costs. The prices for oil & gas and coal depend upon factors beyond our control, including: ​ ● overall domestic and global economic conditions; ● the supply of and demand for domestic and foreign coal; ● the supply of and demand for oil & gas; ● weather conditions and patterns that affect demand for coal and oil & gas, or our ability to produce coal or the ability of operators to produce oil & gas from our mineral interests; ● supply chain and cost of raw materials for coal and oil & gas operations; ● the adverse impact of pandemics, outbreaks and other public health events; ● the proximity to and capacity of transportation facilities; ● competition from other coal suppliers; ● domestic and foreign governmental regulations and taxes; ● the price and availability of alternative fuels; ● the effect of worldwide energy consumption, including the impact of technological advances on energy consumption; ● international developments impacting the supply of coal; ● international developments impacting the supply of oil & gas; and ● the impact of domestic and foreign governmental laws and regulations. ​ Any adverse change in these factors could result in weaker demand and lower prices for our products. A substantial or extended decline in coal prices could materially and adversely affect us by decreasing our revenues to the extent we are not protected by the terms of existing coal supply agreements. ​ Competition within the coal industry could adversely affect our ability to sell coal. In addition, foreign currency fluctuations could adversely affect the competitiveness of our coal abroad. ​ We compete with other coal producers in various regions of the United States for domestic coal sales. In addition, we face competition from foreign and domestic producers that sell their coal in the international coal markets. The most important factors on which we compete are delivered price ( i.e. , the cost of coal delivered to the customer, including transportation costs, which are generally paid by our customers either directly or indirectly), coal quality characteristics, contract flexibility ( e.g. , volume optionality and multiple supply sources), and reliability of supply. Some competitors could have, among other things, larger financial and operating resources, lower per ton cost of production, or relationships with specific transportation providers. The competition among coal producers could impact our ability to retain or attract customers and could adversely impact our revenues and cash available for distribution. ​ We sell coal in the export thermal and metallurgical coal market, both of which are significantly affected by international demand and competition. Consolidation in the coal industry or current or future bankruptcy proceedings of coal competitors could adversely affect us. The prices of and demand for our coal could significantly decline, which could have a material adverse effect on our business, financial condition, results of operations, and cash flows, and could reduce our revenues and cash available for distribution. ​ In addition, we face competition from foreign producers that sell their coal in the export market. Potential changes to international trade agreements, trade concessions, or other political and economic arrangements could benefit coal producers operating in countries other than the United States. We could be adversely impacted on the basis of price or other factors by foreign trade policies or other arrangements that benefit competitors. In addition, coal is sold internationally in United States dollars and, as a result, general economic conditions in foreign markets and changes in foreign currency exchange rates could provide our foreign competitors with a competitive advantage. If our competitors' currencies decline against the United States dollar or foreign purchasers' local currencies, those competitors could be able 37 Table of Contents to offer lower prices for coal to those purchasers. Furthermore, if the currencies of overseas purchasers were to significantly decline in value in comparison to the United States dollar, those purchasers may seek decreased prices for the coal we sell. Consequently, currency fluctuations could adversely affect the competitiveness of our coal in international markets, which could have a material adverse effect on our business, financial condition, results of operations, and cash flows. ​ Changes in taxes or tariffs and other trade measures by the United States and foreign governments could adversely affect our results of operations, financial position, and cash flows. ​ We pay certain taxes and fees related to our operations. Congress or state legislatures may seek to increase these taxes and fees that relate specifically to the coal industry. We cannot predict further developments, and such increases could have a material adverse effect on our results of operations, financial position, and cash flows. ​ New tariffs and other trade measures could adversely affect our results of operations, financial position, and cash flows. In response to tariffs imposed by the United States, the European Union, Canada, Mexico, and China have imposed tariffs on United States goods and services. The new tariffs, along with any additional tariffs or trade restrictions that may be implemented by the United States or retaliatory trade measures or tariffs implemented by other countries, could result in reduced economic activity, increased costs in operating our business, reduced demand and changes in purchasing behaviors for thermal and metallurgical coal, limits on trade with the United States or other potentially adverse economic outcomes. Additionally, we sell coal into the export thermal and metallurgical markets. Accordingly, our international sales could also be impacted by the tariffs and other restrictions on trade between the United States and other countries. While tariffs and other retaliatory trade measures imposed by other countries on United States goods have not yet had a significant impact on our business or results of operations, we cannot predict further developments, and such existing or future tariffs could have a material adverse effect on our results of operations, financial position and cash flows and could reduce our revenues and cash available for distribution. ​ Global geopolitical tensions have caused, and may cause in the future, significant market disruptions that may lead to increased volatility in the price of commodities, including oil & gas, coal, and other sources of energy. ​ Volatility in coal and oil & gas prices has been and may continue to be heightened as a result of the ongoing Russian-Ukrainian conflict, continued hostilities in the Middle East between Israel and Hamas and the potential impact to global shipping caused by Houthi rebels in Yemen. Globally, various governments have banned imports from Russia including commodities such as oil & gas and coal. These events have caused volatility in the aforementioned commodity markets. Although we have not experienced any material adverse effect on our results of operations, financial condition or cash flows as a result of such conflicts or the resulting volatility, such volatility, may significantly affect prices for our coal and oil & gas or the cost of supplies and equipment, as well as the prices of competing sources of energy for our electric power plant customers. ​ Global geopolitical conflicts, trade and monetary sanctions, as well as any escalation of the conflict and future developments, could significantly affect worldwide market prices and demand for our coal and oil & gas and cause turmoil in the capital markets and generally in the global financial system. Additionally, the geopolitical and macroeconomic consequences of such conflicts and any associated sanctions cannot be predicted but could severely impact the world economy. If any of these events occur, the resulting political instability and societal disruption could reduce overall demand for products, causing a reduction in our revenues or an increase in our costs and thereby materially and adversely affecting our results of operations. 38 Table of Contents ​ Changes in consumption patterns by utilities regarding the use of coal, including plans by utilities to shut down or move away from coal-fired generation, have affected our ability to sell the coal we produce and may do so in the future. ​ Our business is closely linked to the demand for electricity, and any changes in coal consumption by domestic or international electric power generators would likely impact our business over the long term. The domestic electric power sector accounts for the vast majority of the total domestic coal consumption. The amount of coal consumed by the domestic electric utility industry is affected primarily by the overall demand for electricity, environmental and other governmental regulations, and the price and availability of competing fuels for power plants such as nuclear, natural gas, and fuel oil as well as alternative sources of energy. Competition from natural gas-fired plants that are relatively more efficient, less expensive to construct, and less difficult to permit than coal-fired plants has the most potential to displace a significant amount of coal-fired electric power generation in the near term, particularly from older, less efficient coal-fired powered generators. ​ Future environmental regulation of GHG emissions also could accelerate the use by utilities of fuels other than coal. In addition, federal and state mandates for increased use of electricity derived from renewable energy sources could affect demand for coal. Such mandates, combined with other incentives to use renewable energy sources such as tax credits, could make alternative fuel sources more competitive with coal. Further, far-reaching federal regulations promulgated by the EPA in the last several years, such as CSAPR and MATS, have led to the premature retirement of coal-fired generating units and a significant reduction in the amount of coal-fired generating capacity in the United States. A decrease in coal consumption by the domestic electric utility industry could adversely affect the demand for or the price of coal, which could negatively impact our results of operations and reduce our cash available for distribution. ​ Other factors, such as efficiency improvements associated with technologies powered by electricity have slowed electricity demand growth and could contribute to slower growth in the future. Further decreases in the demand for electricity, such as decreases that could be caused by a worsening of current economic conditions, could have a material adverse effect on the demand for coal and our business over the long term. ​ We, our customers, or the Operators of our oil & gas mineral interests could be subject to litigation related to climate change . ​ Increasing attention to climate change risk has also resulted in a recent trend of governmental investigations and private litigation by state and local governmental agencies as well as private plaintiffs in an effort to hold energy companies accountable for the alleged effects of climate change. Other public nuisance lawsuits have been brought in the past against power, coal, and oil & gas companies alleging that their operations are contributing to climate change. The plaintiffs in these suits sought various remedies, including punitive and compensatory damages and injunctive relief. While the U.S. Supreme Court held that federal common law provided no basis for public nuisance claims against the defendants in those cases, tort-type liabilities remain a possibility and a source of concern. Government entities in other states (including California and New York) have brought similar claims seeking to hold a wide variety of companies that produce fossil fuels liable for the alleged impacts of the GHG emissions attributable to those fuels. Those lawsuits allege damages as a result of climate change and the plaintiffs are seeking unspecified damages and abatement under various tort theories. Separately, litigation has been brought against certain fossil-fuel companies alleging that they have been aware of the adverse effects of climate change for some time but failed to adequately disclose such impacts to their investors or consumers. We have not been made a party to these other suits, but it is possible that we could be included in similar future lawsuits initiated by state and local governments as well as private claimants. ​ Litigation resulting from disputes with our customers could result in substantial costs, liabilities, and loss of revenues. ​ From time to time, we have disputes with our customers over the provisions of coal supply contracts relating to, among other things, coal pricing, quality, quantity, and the existence of specified conditions beyond our or our customers' control that suspend performance obligations under the particular contract. Disputes could occur in the future and we may not be able to resolve those disputes in a satisfactory manner, which could have a material adverse effect on our business, financial condition, and results of operations. ​ 39 Table of Contents Our profitability could decline due to unanticipated mine operating conditions and other events that are not within our control and that may not be fully covered under our insurance policies. ​ Our coal mining operations are influenced by changing conditions or events that can affect production levels and costs at particular mines for varying lengths of time and, as a result, can diminish our profitability. These conditions and events include, among others: ​ ● mining and processing equipment failures and unexpected maintenance problems; ● unavailability of required equipment; ● prices for fuel, steel, explosives, and other supplies; ● fines and penalties incurred as a result of alleged violations of environmental and safety laws and regulations; ● variations in the thickness of the layer, or seam, of coal; ● amounts of overburden, partings, rock, and other natural materials; ● weather conditions, such as heavy rains, flooding, ice, and other natural events affecting operations, transportation, or customers; ● accidental mine water discharges and other geological conditions; ● fires; ● seismic activities, ground failures, rock bursts or structural cave-ins or slides; ● employee injuries or fatalities; ● labor-related interruptions; ● increased reclamation costs; ● inability to acquire, maintain or renew mining rights or permits in a timely manner, if at all; ● fluctuations in transportation costs and the availability or reliability of transportation; and ● unexpected operational interruptions due to other factors. ​ These conditions have the potential to significantly impact our operating results. Prolonged disruption of production at any of our mines would result in a decrease in our revenues and profitability, which could materially adversely impact our quarterly or annual results. ​ Effective October 1, 2023, we renewed our property and casualty insurance program through September 30, 2024. Our property insurance was procured from our wholly owned captive insurance company, Wildcat Insurance. Wildcat Insurance charged certain of our subsidiaries for the premiums on this program and in return purchased reinsurance for the program in the standard market. The maximum limit in the commercial property program is $100.0 million per occurrence, excluding a $1.5 million deductible for property damage, a 75 or 90 day waiting period for underground business interruption depending on the mining complex and an additional $25.0 million overall aggregate deductible. We retained a 7.25% participating interest in our current commercial property insurance program. We can make no assurances that we will not experience significant insurance claims in the future that could have a material adverse effect on our business, financial condition, results of operations and ability to purchase property insurance in the future. Also, exposures exist for which no insurance may be available and for which we have not reserved. In addition, the insurance industry has been subject to efforts by environmental activists to restrict coverages available for fossil-fuel companies. ​ We could be unable to obtain and renew permits necessary for our coal mining operations, which could reduce our production, cash flow, and profitability. ​ Mining companies must obtain numerous governmental permits or approvals that impose strict conditions and obligations relating to various environmental and safety matters in connection with coal mining. The permitting rules are complex and can change over time. Regulatory authorities exercise considerable discretion in the timing and scope of permit issuance. The public has the right to comment on permit applications and otherwise participate in the permitting process, including through court intervention. Accordingly, permits required to conduct our operations may not be issued, maintained, or renewed, may not be issued or renewed in a timely fashion, or may involve requirements that restrict our ability to economically conduct our mining operations. Limitations on our ability to conduct our mining operations due to the inability to obtain or renew necessary permits or similar approvals could reduce our production, cash flow, and profitability. Please read "Item 1. Business—Environmental, Health and Safety Regulations— Mining Permits and Approvals ." ​ 40 Table of Contents The EPA has begun reviewing permits required for the discharge of overburden from mining operations under Section 404 of the CWA. Various initiatives by the EPA regarding these permits have increased the time required to obtain and the costs of complying with such permits. In addition, the EPA previously exercised its "veto" power to withdraw or restrict the use of previously issued permits in connection with one of the largest surface mining operations in Appalachia. The EPA's action was ultimately upheld by a federal court. As a result of these developments, we could be unable to obtain or experience delays in securing, utilizing, or renewing Section 404 permits required for our operations, which could have an adverse effect on our results of operation and financial position. Please read "Item 1. Business—Environmental, Health and Safety Regulations— Water Discharge ." ​ In addition, some of our permits could be subject to challenges from the public, which could result in additional costs or delays in the permitting process or even an inability to obtain permits, permit modifications, or permit renewals necessary for our operations. ​ Fluctuations in transportation costs and the availability or reliability of transportation could reduce revenues by causing us to reduce our production or by impairing our ability to supply coal to our customers. ​ Transportation costs represent a significant portion of the total cost of coal for our customers and, as a result, the cost of transportation is a critical factor in a customer's purchasing decision. Increases in transportation costs could make coal a less competitive source of energy or could make our coal production less competitive than coal produced from other sources. Disruption of transportation services due to weather-related problems, flooding, drought, accidents, mechanical difficulties, strikes, lockouts, bottlenecks, or other events could temporarily impair our ability to supply coal to our customers. Our transportation providers could face difficulties in the future that could impair our ability to supply coal to our customers, resulting in decreased revenues. If there are disruptions in the transportation services provided by our primary rail or barge carriers that transport our coal and we are unable to find alternative transportation providers to ship our coal, our business could be adversely affected. ​ Conversely, significant decreases in transportation costs could result in increased competition from coal producers in other parts of the country. For instance, difficulty in coordinating the many eastern coal loading facilities, the large number of small shipments, the steeper average grades of the terrain, and a more unionized workforce are all issues that combine to make coal shipments originating in the eastern United States inherently more expensive on a per-mile basis than coal shipments originating in the western United States. Historically, high coal transportation rates from the western coal-producing areas into certain eastern markets limited the use of western coal in those markets. Lower rail rates from the western coal-producing areas to markets served by eastern United States coal producers have created major competitive challenges for eastern coal producers. In the event of further reductions in transportation costs from western coal-producing areas, the increased competition with certain eastern coal markets could have a material adverse effect on our business, financial condition, and results of operations. ​ States in which our coal is transported by truck may modify or increase enforcement of their laws regarding weight limits or coal trucks on public roads. Such legislation and enforcement efforts could result in shipment delays and increased costs. An increase in transportation costs could have an adverse effect on our ability to increase or maintain production and could adversely affect revenues. ​ Political or financial instability, currency fluctuations, the outbreak of pandemics or other illnesses (such as the COVID-19 pandemic), labor unrest, transport capacity and costs, port security, weather conditions, natural disasters, or other events that could alter or suspend our operations, slow or disrupt port activities, or affect foreign trade are beyond our control and could materially disrupt our ability to participate in the export market for coal sales, which could adversely affect our sales and our results of operations. ​ Unexpected increases in raw material costs could significantly impair our operating profitability. ​ Our coal mining operations are affected by commodity prices. We use significant amounts of steel, petroleum products, and other raw materials in various pieces of mining equipment, supplies, and materials, including the roof bolts required by the room-and-pillar method of mining. Steel prices and the prices of scrap steel, natural gas, and coking coal consumed in the production of iron and steel fluctuate significantly and could change unexpectedly. Inflationary pressures have and could continue to lead to price increases affecting many of the components of our operating expenses such as fuel, steel, and maintenance expenses. There could be acts of nature or terrorist attacks or threats that could also impact the future 41 Table of Contents costs of raw materials. Future volatility in the price of steel, petroleum products, or other raw materials will impact our operational expenses and could result in significant fluctuations in our profitability. ​ A shortage of skilled labor may make it difficult for us to maintain labor productivity and competitive costs and could adversely affect our profitability. ​ Efficient coal mining using modern techniques and equipment requires skilled laborers, preferably with at least one year of experience and proficiency in multiple mining tasks. In recent years, a shortage of experienced coal miners has caused us to include some inexperienced staff in the operation of certain mining units, which decreases our productivity and increases our costs. This shortage of experienced coal miners is the result of a significant percentage of experienced coal miners reaching retirement age, combined with the difficulty of retaining existing workers and attracting new workers to the coal industry. Thus, this shortage of skilled labor could continue over an extended period. If the shortage of experienced labor continues or worsens, it could have an adverse impact on our labor productivity and costs and our ability to expand production in the event there is an increase in the demand for our coal, which could adversely affect our profitability. ​ Disruptions in supply chains could significantly impair our operating profitability. ​ We are dependent upon vendors to supply mining equipment, safety equipment, supplies, and materials. If a vendor fails to deliver on its commitments, or if common carriers have difficulty providing capacity to meet demands for their services, we could experience reductions in our production or increased production costs, which could lead to reduced profitability and adversely affect our results of operations. ​ Inflationary pressures could significantly impair our operating profitability. ​ Any future inflationary or deflationary pressures could adversely affect the results of our operations. For example, at times our results have been significantly impacted by price increases affecting many of the components of our operating expenses such as fuel, steel, maintenance expense and labor. In addition to potential cost increases, inflation could cause a decline in global or regional economic conditions that reduce demand for our coal or oil & gas and could adversely affect our results of operations. ​ The unavailability of an adequate supply of coal mineral reserves and resources that can be mined at competitive costs could cause our profitability to decline. ​ Our profitability depends substantially on our ability to mine coal mineral reserves and resources that have the geological characteristics that enable them to be mined at competitive costs and to meet the quality needed by our customers. Because we deplete our reserves and resources as we mine coal, our future success and growth depend, in part, upon our ability to acquire additional coal mineral reserves and resources that are economically recoverable. Replacement reserves and resources may not be available when required or, if available, may not be mineable at costs comparable to those of the depleting mines. We may not be able to accurately assess the geological characteristics of any reserves or resources that we acquire, which could adversely affect our profitability and financial condition. Exhaustion of reserves and resources at particular mines also could have an adverse effect on our operating results that is disproportionate to the percentage of overall production represented by such mines. Our ability to obtain other reserves and resources in the future could be limited by restrictions under our existing or future debt agreements, competition from other coal companies for attractive properties, the lack of suitable acquisition candidates, or the inability to acquire coal properties on commercially reasonable terms. ​ The estimates of our coal mineral reserves and resources could prove inaccurate and could result in decreased profitability. ​ The estimates of our coal mineral reserves and resources could vary substantially from the actual amounts of coal we are able to economically recover. The reserve and resource data set forth in "Item 2. Properties—Coal Mineral Resources and Reserves" represent engineering estimates. All of the coal mineral reserves presented in this Annual Report on Form 10-K constitute proven and probable mineral reserves. There are numerous uncertainties inherent in estimating quantities of reserves and resources, including many factors beyond our control. Estimates of coal mineral reserves and 42 Table of Contents resources necessarily depend upon a number of variables and assumptions, any one of which could vary considerably from actual results. These factors and assumptions relate to: ​ ● geological and mining conditions, which may not be fully identified by available exploration data and/or differ from our experiences in areas where we currently mine; ● the percentage of coal in the ground ultimately recoverable; ● historical production from the area compared with production from other producing areas; ● the assumed effects of regulation and taxes by governmental agencies; ● future improvements in mining technology; and ● assumptions concerning future coal prices, operating costs, capital expenditures, severance and excise taxes, and development and reclamation costs. ​ Each of the factors which impacts reserve and resource estimation may vary considerably from the assumptions used in making the estimation and, as a result, the estimates in this report may not accurately reflect our actual coal reserves and resources. Actual production, revenues and expenditures with respect to our coal reserves will likely vary from the assumptions used in these estimates, and these variances may be material. Government regulations and other pressures may result in the closure of coal-fired electric generating plants earlier than assumed. Such changes would reduce the economic viability of our mining operations and could have a material adverse impact on our operations and financial results. ​ Coal mining in certain areas in which we operate is more difficult and involves more regulatory constraints than mining in other areas of the United States, which could affect the mining operations and cost structures of these areas. ​ The geological characteristics of some of our coal mineral reserves, such as depth of overburden and coal seam thickness, make them difficult and costly to mine. As mines become depleted, replacement reserves may not be available when required or, if available, may not be mineable at costs comparable to those of the depleting mines. In addition, permitting, licensing, and other environmental and regulatory requirements associated with certain of our mining operations are more costly and time-consuming to satisfy. Subsidence issues are particularly important to our operations engaged in longwall mining. Failure to timely and economically secure subsidence rights or any associated mitigation agreements could materially affect our results by causing delays or changes in our mining plan. These factors could materially adversely affect the mining operations and cost structures of, and our customers' ability to use coal produced by, our mines. ​ Extensive environmental laws and regulations affect coal consumers and could affect the demand for coal as a fuel source. ​ Federal, state, and local laws and regulations extensively regulate the amount of sulfur dioxide, particulate matter, nitrogen oxides, mercury, and other compounds emitted into the air from coal-fired electric power plants, which are the ultimate consumers of much of our coal. These laws and regulations can require significant emission control expenditures for many coal-fired power plants, and various new and proposed laws and regulations could require further emission reductions and associated emission control expenditures. These laws and regulations could affect demand and prices for coal. There is also continuing pressure on federal and state regulators to impose limits on carbon dioxide emissions from electric power plants, particularly coal-fired power plants. Further, far-reaching federal regulations promulgated by the EPA in the last several years, such as CSAPR and MATS, have led to the premature retirement of coal-fired generating units and a significant reduction in the amount of coal-fired generating capacity in the United States. Please read "Item 1. Business—Environmental, Health and Safety Regulations— Air Emissions ," "— GHG Emissions " and "— Hazardous Substances and Wastes ." ​ Our coal mining operations are subject to extensive and costly laws and regulations, and such current and future laws and regulations could increase current operating costs or limit our ability to produce coal. ​ We are subject to numerous federal, state, and local laws and regulations affecting the coal mining industry, including laws and regulations pertaining to employee health and safety, permitting and licensing requirements, air and water quality standards, plant and wildlife protection, reclamation and restoration of mining properties after mining is completed, the discharge or release of materials into the environment, surface subsidence from underground mining, and the effects that mining has on groundwater quality and availability. Certain of these laws and regulations may impose strict liability without regard to fault or legality of the original conduct. Failure to comply with these laws and regulations may result in 43 Table of Contents the assessment of administrative, civil, and criminal penalties, the imposition of remedial liabilities, and the issuance of injunctions limiting or prohibiting the performance of operations. Complying with these laws and regulations could be costly and time-consuming and could delay the commencement or continuation of exploration or production operations. The possibility exists that new laws or regulations may be adopted, or that judicial interpretations or more stringent enforcement of existing laws and regulations may occur, which could materially affect our mining operations, cash flow, and profitability, either through direct impacts on our mining operations, or indirect impacts that discourage or limit our customers' use of coal. Please read "Item 1. Business—Environmental, Health and Safety Regulations." ​ Federal and state laws addressing mine safety practices impose stringent reporting requirements and civil and criminal penalties for violations. Federal and state regulatory agencies continue to interpret and implement these laws and propose new regulations and standards. Implementing and complying with these laws and regulations has increased and will continue to increase our operational expenses and have an adverse effect on our results of operation and financial position. For more information, please read "Item 1. Business—Environmental, Health and Safety Regulations— Mine Health and Safety Laws ." ​ Oil & gas operations are subject to various governmental laws and regulations. Compliance with these laws and regulations can be burdensome and expensive for the Operators, and failure to comply could result in the Operators incurring significant liabilities, either of which could impact the Operators' willingness to develop our interests. ​ The Operators' operations on the properties in which we hold interests are subject to various federal, state, and local governmental regulations that may change from time to time in response to economic and political conditions. Matters subject to regulation include drilling operations, production and distribution activities, discharges or releases of pollutants or wastes, plugging and abandonment of wells, maintenance and decommissioning of other facilities, the spacing of wells, unitization and pooling of properties, and taxation. From time to time, regulatory agencies have imposed price controls and limitations on production by restricting the rate of flow of oil & gas wells below actual production capacity to conserve supplies of oil & gas. In addition, the production, handling, storage, and transportation of oil & gas, as well as the remediation, emission, and disposal of oil & gas wastes, by-products thereof, and other substances and materials produced or used in connection with oil & gas operations are subject to regulation under federal, state, and local laws and regulations primarily relating to the protection of worker health and safety, natural resources, and the environment. Failure to comply with these laws and regulations may result in the assessment of sanctions on the Operators, including administrative, civil, or criminal penalties, permit revocations, requirements for additional pollution controls, and injunctions limiting or prohibiting some or all of the Operators' operations on our properties. Moreover, these laws and regulations have generally imposed increasingly strict requirements related to water use and disposal, air pollution control, and waste management. Laws and regulations governing exploration and production may also affect production levels. The Operators must comply with federal and state laws and regulations governing conservation matters, including: ​ ● provisions related to the unitization or pooling of the oil & gas properties; ● the establishment of maximum rates of production from wells; ● the spacing of wells; ● the plugging and abandonment of wells; and ● the removal of related production equipment. ​ Additionally, federal and state regulatory authorities may expand or alter applicable pipeline-safety laws and regulations, compliance with which could require increased capital costs for third-party oil & gas transporters. These transporters may attempt to pass on such costs to the Operators, which in turn could affect profitability on the properties in which we own mineral interests. ​ The Operators must also comply with laws and regulations prohibiting fraud and market manipulations in energy markets. To the extent the operators of our properties are shippers on interstate pipelines, they must comply with the tariffs of those pipelines and with federal policies related to the use of interstate capacity. The Operators may be required to make significant expenditures to comply with the governmental laws and regulations described above and may be subject to potential fines and penalties if they are found to have violated these laws and regulations. We believe the trend of more expansive and stricter environmental legislation and regulations will continue. These current laws and regulations and other potential regulations could increase the operating costs of the Operators and delay production and could ultimately impact the Operators' ability and willingness to develop our properties. ​ 44 Table of Contents Federal and state legislative and regulatory initiatives relating to hydraulic fracturing could result in increased costs, additional operating restrictions or delays, and fewer potential drilling locations, which could adversely affect revenues from our mineral interests. ​ Oil & gas production on the properties in which we hold mineral interests utilizes hydraulic fracturing. Hydraulic fracturing is a common practice that is used to stimulate the production of hydrocarbons from tight formations, including shales. The process involves the injection of water, sand, and chemicals under pressure into formations to fracture the surrounding rock and stimulate production. The Federal Safe Drinking Water Act regulates the underground injection of substances through the UIC program. Hydraulic fracturing is generally exempt from regulation under the UIC program, and the hydraulic-fracturing process is typically regulated by state oil & gas commissions. ​ Several states where we own interests, including Texas and Oklahoma, have adopted regulations that could restrict or prohibit hydraulic fracturing in certain circumstances or require the disclosure of the composition of hydraulic-fracturing fluids. In addition to state laws, local land-use restrictions, such as city ordinances, may restrict or prohibit the performance of well drilling in general or hydraulic fracturing in particular. We cannot predict what additional state or local requirements may be imposed in the future on oil & gas operations in the states in which we own interests. In the event state, local, or municipal legal restrictions are adopted in areas where the Operators conduct operations, the Operators could incur substantial costs to comply with these requirements, which could be significant in nature, experience delays, or curtailment in the pursuit of exploration, development, or production activities and perhaps even be precluded from the drilling of wells. ​ There has been increasing public controversy regarding hydraulic fracturing about increased risks of induced seismicity, the use of fracturing fluids, impacts on drinking water supplies, use of water, and the potential for impacts to surface water, groundwater, and the environment generally. A number of lawsuits and enforcement actions have been initiated across the country implicating hydraulic-fracturing practices. If new laws or regulations are adopted that significantly restrict hydraulic fracturing, those laws could make it more difficult or costly for the Operators to perform fracturing to stimulate production from tight formations. In addition, if hydraulic fracturing is further regulated at the federal or state level, fracturing activities on our properties could become subject to additional permitting and financial assurance requirements, more stringent construction specifications, increased monitoring, reporting and recordkeeping obligations, plugging and abandonment requirements, and also to attendant permitting delays and potential increases in costs. Legislative changes could cause operators to incur substantial compliance costs and adversely affect revenues from our mineral interests. At this time, it is not possible to estimate the impact on our business of newly enacted or potential federal or state legislation governing hydraulic fracturing. ​ Legislation or regulatory initiatives intended to address seismic activity could restrict the Operators' drilling and production activities, as well as their ability to dispose of produced water gathered from such activities, which could have a material adverse effect on our business. ​ State and federal regulatory agencies have recently focused on a possible connection between the hydraulic-fracturing related activities, particularly the underground injection of wastewater into disposal wells, and the increased occurrence of seismic activity, and regulatory agencies at all levels are continuing to study the possible linkage between oil & gas activity and induced seismicity. ​ In addition, a number of lawsuits have been filed in other states, including in Oklahoma, alleging that disposal well operations have caused damage to neighboring properties or otherwise violated state and federal rules regulating waste disposal. In response to these concerns, regulators in some states are seeking to impose additional requirements, including requirements in the permitting of produced water disposal wells or otherwise to assess the relationship between seismicity and the use of such wells. For example, both Texas and Oklahoma have imposed certain limits on the permitting or operation of disposal wells in areas with increased instances of induced seismic events. In September 2021, the TRRC issued a notice to operators in the Midland area to reduce saltwater disposal well activities and provide certain data to the TRRC. Subsequently, the TRRC ordered the indefinite suspension of all deep oil & gas-produced water injection wells in the area, effective December 31, 2021. Relatedly, in March 2022, the TRRC began implementation of its Northern Culberson-Reeves Seismic Response Action Plan to address injection-induced seismicity with the goal to eliminate 3.5 magnitude or greater earthquakes no later than December 31, 2023. In response to continued seismicity in the area, the TRRC issued a notice that it is suspending all disposal wells in the Northern Culberson-Reeves Seismic Response Area, effective January 12, 2024. ​ 45 Table of Contents The adoption or implementation of any new laws or regulations that restrict the Operators' ability to use hydraulic fracturing or dispose of produced water gathered from drilling and production activities by limiting volumes, disposal rates, disposal well locations, or otherwise, or requiring the Operators to shut down or limit the operation of disposal wells, could have a material adverse effect on our business, financial condition and results of operations. ​ Our coal operations, and the third-party operations related to our oil and gas mineral interests, are subject to a series of risks resulting from climate change. ​ Combustion of fossil fuels, such as the coal we produce and the oil & gas produced from our mineral interests, results in the emission of carbon dioxide into the atmosphere. Concerns about the environmental impacts of such emissions have resulted in a series of regulatory, political, litigation, and financial risks for our business. Global climate issues continue to attract public and scientific attention. Most scientists have concluded that increasing concentrations of GHGs in the Earth's atmosphere could produce climate changes that have significant physical effects, such as increased frequency and severity of storms, droughts and floods, and other climatic events. Increasing government attention is being paid to global climate issues and to emissions of GHGs, including emissions due to fossil fuels. ​ In the United States, no comprehensive climate change legislation has been implemented at the federal level. However, following the U.S. Supreme Court finding that GHG emissions constitute a pollutant under the CAA, the EPA has adopted regulations that, among other things, establish construction and operating permit reviews for GHG emissions from certain large stationary sources, require the monitoring and annual reporting of GHG emissions from certain sources in the United States, or constrain the emissions of powerplants (though such emissions restraints have been subject to challenge; for more information, see our regulatory disclosure titled "GHG emissions"). Additionally, the U.S. Congress approved, and President Biden signed into law, a resolution under the Congressional Review Act to repeal September 2020 revisions to methane standards, effectively reinstating the more stringent 2016 standards. Furthermore, in December 2023, EPA issued its final methane rules, known as OOOOb and OOOOc, that established new sources and first-time existing source standards of performance for methane and volatile organic compound emissions for oil & gas facilities. The final rules include nationwide emissions guidelines for states to limit methane emissions from existing crude oil and natural gas facilities and states have two years to prepare and submit their plants to impose methane emission controls on existing sources. The rules also revise requirements for fugitive emissions monitoring and repair as well as equipment leaks and the frequency of monitoring surveys and establishes a "super-emitter" response program to timely mitigate emissions events. It is likely that the final rule will be subject to legal challenges. Moreover, compliance with the new rules may effect the amount oil and gas companies owe under the Inflation Reduction Act, which amended the CAA to impose a first-time fee on the emission of methane from sources required to report their GHG emissions to the EPA. The methane emissions fee applies to excess methane emissions from certain facilities and starts at $900 per metric ton of leaked methane in 2024 and increases to $1,200 in 2025 and $1,500 in 2026 and thereafter. Compliance with the EPA’s new final rules would exempt an otherwise covered facility from the requirement to pay the methane fee. We cannot predict the scope of any final methane regulatory requirements or the cost for the Operators to comply with such requirements. However, given the long-term trend toward increasing regulation, future federal GHG regulations of the oil and gas industry remain a significant possibility and may have an impact on drilling operations on our oil & gas mineral interests. ​ Separately, various states and groups of states have adopted or are considering adopting legislation, regulations, or other regulatory initiatives that are focused on such areas as GHG cap-and-trade programs, carbon taxes, reporting and tracking programs, and restriction of emissions. Internationally, the Paris Agreement requires member states to submit non-binding, individually-determined emissions reduction targets. These commitments could further reduce demand and prices for fossil fuels. Although the United States had withdrawn from the Paris Agreement, following President Biden's executive order in January 2021, the United States rejoined the Agreement and, in April 2021, established a goal of reducing economy-wide net GHG emissions 50-52% below levels by 2030. Additionally, at COP26 in Glasgow in November 2021, the United States and the European Union jointly announced the launch of a Global Methane Pledge committing to a collective goal of reducing global methane emissions by at least 30% from 2020 levels by 2030, including "all feasible reductions" in the energy sector. At COP27 in Sharm El-Sheik in November 2022, countries reiterated the agreements from COP26 and were called upon to accelerate efforts toward the phase out of inefficient fossil fuel subsidies. The United States also announced, in conjunction with the European Union and other partner countries, that it would develop standards for monitoring and reporting methane emissions to help create a market for low methane-intensity natural gas. Although no firm commitment or timeline to phase out or phase down all fossil fuels was made at COP27, there can be no guarantees that countries will not seek to implement such a phase out in the future. In December 2023, the United Arab Emirates hosted COP28 where parties agreed to transition "away from fossil fuels in energy systems in a just, orderly and equitable manner" and increase renewable energy capacity so as to achieve net zero by 2050, although no 46 Table of Contents timeline for doing so was set. The full impact of these actions is uncertain at this time and it is unclear what additional initiatives may be adopted or implemented that may have adverse effects on us and the Operators' operations. ​ Governmental, scientific, and public concern over climate change has also resulted in increased political risks, including certain climate-related pledges made by certain candidates now in political office. In January 2021, President Biden issued an executive order that commits to substantial action on climate change, calling for, among other things, the increased use of zero-emissions vehicles by the federal government, the elimination of subsidies provided to the fossil-fuel industry, a doubling of electricity generated by offshore wind by 2030, and increased emphasis on climate-related risks across governmental agencies and economic sectors. Other actions that may be pursued include restrictive requirements on new pipeline infrastructure or fossil-fuel export facilities or the promulgation of a carbon tax or cap and trade program. Further, although Congress has not passed such legislation, almost half of the states have begun to address GHG emissions, primarily through the planned development of emissions inventories, regional GHG cap and trade programs, or the establishment of renewable energy requirements for utilities. Depending on the particular program, we, our customers, or operators of our mineral interests could be required to control GHG emissions or to purchase and surrender allowances for GHG emissions resulting from our operations. Litigation risks are also increasing. For more information, see our risk factor titled "We, our customers, or the Operators of our oil & gas mineral interests could be subject to litigation related to climate change." ​ Apart from governmental regulation, there are also increasing financial risks for fossil-fuel producers as stakeholders of fossil-fuel energy companies may elect in the future to shift some or all of their support into non-energy related sectors. Institutional lenders who provide financing to fossil-fuel energy companies also have become more attentive to sustainable lending practices and some of them may elect not to provide funding for fossil-fuel energy companies. For example, at COP26, the GFANZ announced that commitments from over 450 firms across forty-five countries had resulted in over $130 trillion in capital committed to net zero goals. The various sub-alliances of GFANZ generally require participants to set short-term, sector-specific targets to transition their financing, investing, and/or underwriting activities to net zero emissions by 2050. There is also a risk that financial institutions will be required to adopt policies that have the effect of reducing the funding provided to the fossil-fuel sector. For example, in October 2023, the Federal Reserve, Office of the Comptroller of the Currency and the Federal Deposit Insurance Corp. released a finalized set of principles guiding financial institutions with $100 billion or more in assets on the management of physical and transition risks associated with climate change on specific assets of the banks' portfolio. Although we cannot predict the effects of these actions, such limitation of investments in and financing, bonding, and insurance coverages for fossil-fuel energy companies could adversely affect our coal mining or oil & gas production activities. ​ Separately, the SEC released a proposed rule in March 2022 that would establish a framework for the reporting of climate risks, targets and metrics. A final rule is anticipated to be released in the second quarter of 2024. The SEC has also announced that it is scrutinizing existing climate-change related disclosures in public filings, increasing the potential for enforcement if the SEC were to allege that an issuer’s existing climate disclosures are misleading, deceptive, or deficient. Such agency action could also increase the potential for private litigation. Relatedly, California has enacted new laws requiring additional disclosure with respect to certain climate-related risks and GHG emission reduction claims. Other states are considering similar laws. Non-compliance with these new laws may result in the imposition of substantial fines or penalties. Any new laws or regulations imposing more stringent requirements on our business related to the disclosure of climate related risks may result in reputation harms among certain stakeholders if they disagree with our approach to mitigating climate-related risks, increased compliance costs resulting from the development of any disclosures, and increased costs of and restrictions on access to capital to the extent we do not meet any climate-related expectations or requirements of financial institutions. ​ The adoption and implementation of new or more stringent international, federal, or state legislation, regulations, or other regulatory initiatives that impose more stringent standards for GHG emissions from fossil-fuel companies could result in increased costs of compliance or costs of consuming, and thereby reduce demand for coal and oil & gas, which could reduce the profitability of our interests. Additionally, political, litigation, and financial risks could result in either us or oil & gas operators restricting or canceling mining or oil & gas production activities, incurring liability for infrastructure damages as a result of climatic changes, or having an impaired ability to continue to operate economically. One or more of these developments, as well as concerted conservation and efficiency efforts that result in reduced electricity consumption, and consumer and corporate preferences for non-fossil-fuel sources, including alternative energy sources, 47 Table of Contents could cause prices and sales of our coal and/or oil & gas to materially decline and could cause our costs to increase and adversely affect our revenues and results of operations. ​ Climate change may also result in various physical risks, such as the increased frequency or intensity of extreme weather events or changes in meteorological and hydrological patterns that could adversely impact our operations, as well as those of the Operators and their supply chain. Such physical risks may result in damage to our facilities or the Operators' facilities or otherwise adversely impact operations which could decrease the production attributable to our mineral interests. We may not have insurance to cover these risks and the consequences for our or their operations could have a negative impact on the costs and revenues from operations. ​ Some of our operating subsidiaries lease a portion of the surface properties upon which their mining facilities are located. ​ Our operating subsidiaries do not, in all instances, own all of the surface properties upon which their mining facilities have been constructed. Certain of the operating companies have constructed and now operate all or some portion of their facilities on properties owned by third parties with whom our subsidiary has entered into a long-term lease. We have no reason to believe that there exists any risk of loss of these leasehold rights given the terms and provisions of the subject leases and the nature and identity of the third-party lessors; however, in the unlikely event of any loss of these leasehold rights, operations could be disrupted or otherwise adversely impacted as a result of increased costs associated with retaining the necessary land use. ​ Federal and state laws require bonds to secure our obligations related to statutory reclamation requirements and workers ' compensation and black lung benefits. Our inability to acquire or failure to maintain surety bonds that are required by federal and state law would have a material adverse effect on us. ​ Federal and state laws require us to maintain bonds to secure our obligations to repair and return property to its approximate original state after it has been mined (often referred to as "reclaim" or "reclamation"), to pay federal and state workers' compensation and pneumoconiosis (or black lung) benefits, and to satisfy other miscellaneous obligations. These bonds provide assurance that we will perform our statutorily required obligations and are referred to as "surety" bonds. These bonds are typically renewable on a yearly basis. At December 31, 2023, our total of such bonds was $246.9 million. The amount of surety bonding we are required to maintain may be increased by the governmental agencies holding the bond. For example, federal and state regulators are considering making financial assurance requirements more stringent and costly with respect to self-insured coal workers' pneumoconiosis, mine closure and reclamation security amounts. ​ We could have difficulty acquiring or maintaining surety bonds for a variety of reasons, including: ​ ● substantial increases in the amount of bonding required; ● lack of availability, higher expense, or unreasonable terms of new surety bonds, including as a result of external pressures related to fossil-fuel companies; ● the ability of current and future surety bond issuers to increase required collateral, or limitations on the availability of collateral for surety bond issuers due to the terms of our credit agreements; and ● the exercise by third-party surety bondholders of their rights to refuse to renew the surety. ​ Failure to acquire or maintain the required bonds could subject us to fines and penalties, result in the loss of our mining permits, or imperil our ability to self-insure workers compensation and pneumoconiosis obligations, and could have a material adverse effect on us. ​ We depend on unaffiliated Operators for all of the exploration, development, and production of the oil & gas properties in which we own mineral interests. ​ Because we depend on unaffiliated third-party operators for all of the exploration, development, and production of our oil & gas properties, we have little to no control over the operations related to our oil & gas properties. The operators of our properties are often not obligated to undertake any development activities. In the absence of a specific contractual obligation, any development and production activities will be subject to their sole discretion (subject, however, to certain implied obligations to develop imposed by state law). The success and timing of drilling and development activities on our oil & gas properties, and whether the operators elect to drill any additional wells on our acreage, depends on a number of factors that will be largely outside of our control, including: 48 Table of Contents ​ ● the capital costs required for drilling activities by the operators of our oil & gas properties, which could be significantly more than anticipated; ● the ability of the operators of our properties to access capital; ● prevailing commodity prices; ● the availability of suitable drilling equipment, production and transportation infrastructure, and qualified operating personnel; ● the operators' expertise, operating efficiency, and financial resources; ● approval of other participants in drilling wells; ● the operators' expected return on investment in wells drilled on our acreage as compared to opportunities in other areas; ● the selection of technology; ● the selection of counterparties for the marketing and sale of production; and ● the rate of production of the reserves. ​ The Operators may elect not to undertake development activities or may undertake these activities in an unanticipated fashion, which could result in significant fluctuations in our oil & gas revenues. ​ We have little to no control over the timing of future drilling with respect to our oil & gas mineral interests. ​ All of our oil & gas mineral interests may not ultimately be developed or produced by the operators of our properties. Recovery of undeveloped reserves requires significant capital expenditures and successful drilling operations, and the decision to pursue the development of an undeveloped drilling location will be made by the operator and not by us. We generally do not have access to the estimated costs of development of these reserves or the scheduled development plans of the Operators. Our estimate of reserves assumes that substantial capital expenditures are required to develop the reserves. We cannot be certain that the estimated costs of the development of these reserves are accurate, that development will occur as scheduled or that the results of the development will be as estimated. Delays in the development of our reserves, increases in costs to drill and develop our reserves, or decreases in commodity prices will reduce the future net revenues of our estimated undeveloped reserves and could result in some projects becoming uneconomical. In addition, delays in the development of reserves could force us to reclassify certain of our proved undeveloped reserves as unproved reserves. ​ We could experience delays in the payment of royalties and be unable to replace Operators that do not make required royalty payments, and we may not be able to terminate our leases with defaulting lessees if any of the operators on those leases declare bankruptcy. ​ A failure on the part of the Operators of our properties to make royalty payments gives us the right to terminate the lease and enforce payment obligations under the lease. If we terminate any of our leases, we would seek a replacement operator. However, we might not be able to find a replacement operator and, if we did, we might not be able to enter into a new lease on favorable terms within a reasonable period of time. In addition, the outgoing operator could be subject to a proceeding under Bankruptcy Code, in which case our right to enforce or terminate the lease for any defaults, including non-payment, could be substantially delayed or otherwise impaired. In general, in a proceeding under the Bankruptcy Code, the bankrupt operator would have substantial time to decide whether to ultimately reject or assume the lease, which could prevent the execution of a new lease or the assignment of the existing lease to another operator. In the event that the operator rejected the lease, our ability to collect amounts owed would be substantially delayed, and our ultimate recovery could be only a fraction of the amount owed or nothing. In addition, if we are able to enter into a new lease with a new operator, the replacement operator may not achieve the same levels of production or sell oil or natural gas at the same price as the operator it replaced. ​ If the operators of our oil & gas properties suspend our right to receive royalty payments due to title or other issues, our business, financial condition, and/or results of operations could be adversely affected. ​ Upon a change in ownership of mineral interests, and at regular intervals pursuant to routine audit procedures at each of the Operators otherwise at its discretion, the operator of the underlying property has the right to investigate and verify the title and ownership of mineral interests with respect to the properties it operates. If any title or ownership issues are not resolved to its reasonable satisfaction in accordance with customary industry standards, the operator may suspend payment of the related royalty. If an operator of our properties is not satisfied with the documentation we provide to validate our ownership, it may place our royalty payment in suspense until such issues are resolved, at which time we 49 Table of Contents would receive in full payments that would have been made during the suspense period, without interest. Certain of the Operators impose significant documentation requirements for title transfer and may keep royalty payments in suspense for significant periods of time. During the time that an operator puts our assets in pay suspense, we would not receive the applicable mineral or royalty payment owed to us from sales of the underlying oil or natural gas related to such mineral or royalty interest. If a significant amount of our royalty interests is placed in suspense, our results of operations could be reduced significantly. ​ Our estimated oil & gas reserves are based on many assumptions that could turn out to be inaccurate. Any material inaccuracies in these reserve estimates or underlying assumptions will materially affect the quantities and present value of our reserves. ​ Oil & gas reserve engineering is not an exact science and requires subjective estimates of underground accumulations of oil & gas and assumptions concerning future oil & gas prices, production levels, ultimate recoveries, and operating costs. As a result, estimated quantities of proved reserves and projections of future production rates could be incorrect. Our estimates of proved reserves and related valuations as of December 31, 2023, were audited by CGA, which conducted a detailed review of all of our properties at that time using the information provided by us. Over time, we may make material changes to reserve estimates taking into account the results of actual drilling, testing, and production. In addition, certain assumptions regarding future oil & gas prices, production levels, and operating costs could prove incorrect. A meaningful portion of our reserve estimates is made without the benefit of lengthy production history, which is less reliable than estimates based on lengthy production history. Any significant variance from these assumptions to actual figures could greatly affect our estimates of reserves and future cash generated from operations. Numerous changes over time to the assumptions on which our reserve estimates are based, as described above, often result in the actual quantities of oil & gas that are ultimately recovered being different from our reserve estimates. ​ Furthermore, the present value of future net cash flows from our proved reserves is not necessarily the same as the current market value of our estimated reserves. In accordance with rules established by the SEC and the FASB, we base the estimated discounted future net cash flows from our proved reserves on the twelve-month average oil & gas index prices, calculated as the unweighted arithmetic average for the first day-of-the-month price for each month, and costs in effect on the date of the estimate, holding the prices and costs constant throughout the life of the properties. Actual future prices and costs could differ materially from those used in the present value estimate, and future net present value estimates using then-current prices and costs could be significantly less than the current estimate. In addition, the 10% discount factor we use when calculating discounted future net cash flows may not be the most appropriate discount factor based on interest rates in effect from time to time and risks associated with us or the oil & gas industry in general. Please see "Item 2. Properties—Oil & Gas Reserves" for more information on our reserves. ​ Drilling for and producing oil & gas are high-risk activities with many uncertainties that could materially adversely affect our business, financial condition, and results of operations. ​ The drilling activities of the operators of our properties will be subject to many risks. For example, we will not be able to assure our unitholders that wells drilled by the operators of our properties will be productive. Drilling for oil & gas often involves unprofitable efforts, not only from dry wells but also from wells that are productive but do not produce sufficient oil or gas to return a profit at then realized prices after deducting drilling, operating, and other costs. The seismic data and other technologies used do not provide conclusive knowledge prior to drilling a well that oil or gas is present or that it can be produced economically. The costs of exploration, exploitation, and development activities are subject to numerous uncertainties beyond our control and increases in those costs can adversely affect the economics of a project. Further, the Operators' drilling and producing operations could be curtailed, delayed, canceled, or otherwise negatively impacted as a result of other factors, including: ​ ● unusual or unexpected geological formations or earthquakes; ● loss of drilling fluid circulation; ● title problems; ● facility or equipment malfunctions; ● unexpected operational events; ● shortages or delivery delays of equipment and services; ● compliance with environmental and other governmental requirements; and ● adverse weather conditions. ​ 50 Table of Contents Any of these risks can cause substantial losses, including personal injury or loss of life, damage to or destruction of property, natural resources, and equipment, pollution, environmental contamination or loss of wells, and other regulatory penalties. In the event that planned operations, including the drilling of development wells, are delayed or canceled, or existing wells or development wells have lower than anticipated production due to one or more of the factors above or for any other reason, our financial condition, results of operations, and free cash flow could be materially adversely affected. ​ The marketability of oil & gas production is dependent upon transportation and other facilities, certain of which neither we nor the operators of our properties control. If these facilities are unavailable, the Operators' operations could be interrupted and our results of operations and cash available for distribution could be materially adversely affected. ​ The marketability of the Operators' oil & gas production will depend in part upon the availability, proximity, and capacity of transportation facilities, including gathering systems, trucks, and pipelines, owned by third parties. Neither we nor, in general, the operators of our properties control these third-party transportation facilities and the Operators' access to them may be limited or denied. Insufficient production from the wells on our acreage or a significant disruption in the availability of third-party transportation facilities or other production facilities could adversely impact the Operators' ability to deliver to market or produce oil & gas and thereby cause a significant interruption in the Operators' operations. If they are unable, for any sustained period, to implement acceptable delivery or transportation arrangements or encounter production-related difficulties, they may be required to shut-in or curtail production. In addition, the amount of oil & gas that can be produced and sold may be subject to curtailment in certain other circumstances outside of our or the Operators' control, such as pipeline interruptions due to maintenance, excessive pressure, the inability of downstream processing facilities to accept unprocessed gas, physical damage to the gathering system or transportation system or lack of contracted capacity on such systems. The curtailments arising from these and similar circumstances could last from a few days to several months. In many cases, we and the Operators are provided with limited notice, if any, as to when these curtailments will arise and the duration of such curtailments. Any such shut-in or curtailment, or an inability to obtain favorable terms for delivery of the oil & gas produced from our acreage, could adversely affect our financial condition, results of operations, and cash available for distribution. ​ We do not currently enter into hedging arrangements with respect to commodity production from our properties, and we will be exposed to the impact of decreases in the price of such commodities. ​ We have not entered into hedging arrangements to establish, in advance, a price for the sale of the oil & gas or the coal produced from our properties, and we may not enter into such arrangements in the future. As a result, although we could realize the benefit of any short-term increase in the price, we will not be protected against decreases in the price or prolonged periods of low commodity prices, which could materially adversely affect our business, results of operation and cash available for distribution. ​ In the future, we may enter into hedging transactions with the intent of reducing volatility in our cash flows due to fluctuations in the price of oil & gas or coal. However, these hedging activities may not be as effective as we intend in reducing the volatility of our cash flows and, if entered into, are subject to the risks that the terms of the derivative instruments will be imperfect, a counterparty may not perform its obligations under a derivative contract, there could be a change in the expected differential between the underlying commodity price in the derivative instrument and the actual price received, our hedging policies and procedures may not be properly followed and the steps we take to monitor our derivative financial instruments may not detect and prevent violations of our risk management policies and procedures, particularly if deception or other intentional misconduct is involved. Further, we could be limited in receiving the full benefit of increases in commodity prices as a result of these hedging transactions. The occurrence of any of these risks could prevent us from realizing the benefit of a derivative contract. ​ Expansions and acquisitions involve a number of risks, any of which could cause us not to realize the anticipated benefits. ​ Since our formation and the acquisition of our predecessor in August 1999, we have expanded our coal operations by adding and developing mines in existing, adjacent, and neighboring properties. Similarly, the profitability of our business depends significantly upon acquisitions to grow our coal and oil & gas reserves, production, and free cash flow. Our future growth could be limited if we are unable to continue to make acquisitions in either our coal operations or our royalties 51 Table of Contents segments, or if we are unable to successfully integrate the companies, businesses, or properties we acquire. We may not be successful in consummating any acquisitions and the consequences of undertaking these acquisitions are unknown. ​ Competition for acquisitions of coal and oil & gas mineral interests could increase the cost of, or cause us to refrain from, completing acquisitions. Our ability to complete acquisitions is dependent upon, among other things, our ability to obtain debt and equity financing under acceptable terms. In addition, these acquisitions could be in geographic regions in which we do not currently hold properties, which could subject us to additional and unfamiliar legal and regulatory requirements. No assurance can be given that we will be able to identify suitable acquisition opportunities, negotiate acceptable terms, obtain financing for acquisitions on acceptable terms, or successfully acquire identified targets. ​ The process of integrating acquired assets could involve unforeseen difficulties and could require a disproportionate amount of our managerial and financial resources. If we are unable to successfully integrate the companies, businesses, or properties we acquire, our profitability could decline and we could experience a material adverse effect on our business, financial condition, or results of operations. Expansion and acquisition transactions involve various inherent risks, including: ​ ● uncertainties in assessing the value, strengths, and potential profitability of expansion and acquisition opportunities ; ● uncertainties in identifying the extent of all weaknesses, risks, contingent and other liabilities of, expansion and acquisition opportunities; ● the ability to achieve identified operating and financial synergies anticipated to result from an expansion or an acquisition; ● problems that could arise from the integration of the new operations; and ● unanticipated changes in business, industry, or general economic conditions that affect the assumptions underlying our rationale for pursuing the expansion or acquisition opportunity. ​ Any one or more of these factors could cause us not to realize the benefits anticipated to result from an expansion or acquisition. Any expansion or acquisition opportunities we pursue could materially affect our liquidity and capital resources and could require us to incur indebtedness, seek equity capital, or both. Future expansions or acquisitions could result in us assuming more long-term liabilities relative to the value of the acquired assets than we have assumed in our previous expansions and/or acquisitions. ​ The integration of any expansions or acquisitions that we complete will be subject to substantial risks. ​ Even if we make expansions or acquisitions that we believe will increase our coal or mineral revenue, any expansion or acquisition involves potential risks, including, among other things: ​ ● the validity of our assumptions about estimated proved reserves, future production, prices, revenues, capital expenditures, the operating expenses, and costs the Operators would incur to develop the minerals; ● a decrease in our liquidity by using a significant portion of our cash generated from operations or borrowing capacity to finance acquisitions; ● a significant increase in our interest expense or financial leverage if we incur debt to finance acquisitions; ● the assumption of unknown liabilities, losses or costs for which we are not indemnified or for which any indemnity we receive is inadequate; ● mistaken assumptions about the overall cost of equity or debt; ● our ability to obtain satisfactory title to the assets we acquire; ● an inability to hire, train or retain qualified personnel to manage and operate our growing mineral assets; and ● the occurrence of other significant changes, such as impairment of properties, goodwill or other intangible assets, asset devaluation, or restructuring charges. 52 Table of Contents ​ We may not be able to effectively identify investment opportunities in the advancement of energy and related infrastructure on favorable terms, or at all, and failure to do so may limit our future growth. ​ Part of our strategy includes positioning ourselves as a reliable energy provider for the future by pursuing strategic investments that leverage our core competencies and relationships with electric utilities, industrial customers, and federal and state governments. This strategy depends on our ability to successfully identify and evaluate investment opportunities. The number of opportunities may be limited, and we will compete with other investors for these limited opportunities, which could make them more expensive and the returns for our investments less attractive and possibly cause us to refrain from making them at all. Further, certain opportunities will depend on technological and other advancements that may not be within our control and may not come to fruition or be economically feasible in the near term, and we may fail to realize the anticipated benefit of our investments. Any new opportunities also may depend on the viability of new assets or businesses that are contingent on public policy mechanisms including investment tax credits, subsidies, renewable portfolio standards and carbon trading plans. These mechanisms have been implemented at the state and federal levels to support the development of renewable energy, demand-side, and other infrastructure technologies. The availability and continuation of public policy support mechanisms will drive a significant part of the economics and viability of investments generally, as well as our participation in them. ​ Our inability to obtain commercial insurance at acceptable rates or our failure to adequately reserve for self-insured exposures could increase our expenses and have a negative impact on our business. ​ We believe that commercial insurance coverage is prudent in certain areas of our business for risk management. Insurance costs could increase substantially in the future and could be affected by natural disasters, fear of terrorism, financial irregularities, cybersecurity breaches and other fraud at publicly-traded companies, intervention by the government, an increase in the number of claims received by the carriers, and a decrease in the number of insurance carriers. In addition, the carriers with which we hold our policies could go out of business or be otherwise unable to fulfill their contractual obligations or could disagree with our interpretation of the coverage or the amounts owed. In addition, for certain types or levels of risk, such as risks associated with certain natural disasters or terrorist attacks, we may determine that we cannot obtain commercial insurance at acceptable rates, if at all. Therefore, we may choose to forego or limit our purchase of relevant commercial insurance, choosing instead to self-insure one or more types or levels of risks. If we suffer a substantial loss that is not covered by commercial insurance or our self-insurance reserves, the loss and related expenses could harm our business and operating results. Also, exposures exist for which no insurance may be available and for which we have not reserved. In addition, environmental activists could try to hamper fossil-fuel companies by other means including pressuring insurance and surety companies into restricting access to certain needed coverages. ​ Tax Risks to Our Common Unitholders ​ Our tax treatment depends on our status as a partnership for U.S. federal income tax purposes, and our not being subject to a material amount of entity-level taxation. If the IRS were to treat us as a corporation for U.S. federal income tax purposes, or we become subject to entity-level taxation for state tax purposes, our cash available for distribution to you would be substantially reduced. ​ The anticipated after-tax benefit of an investment in our common units depends largely on our being treated as a partnership for U.S. federal income tax purposes. ​ Even though we are organized as a limited partnership under Delaware law, we would be treated as a corporation for U.S. federal income tax purposes unless we satisfy a "qualifying income" requirement. Based on our current operations and current Treasury Regulations, we believe we satisfy the qualifying income requirement. However, we have not requested, and do not plan to request, a ruling from the IRS on this or any other matter affecting us. Failing to meet the qualifying income requirement or a change in current law could cause us to be treated as a corporation for U.S. federal income tax purposes or otherwise subject us to taxation as an entity. ​ If we were treated as a corporation for U.S. federal income tax purposes, we would pay U.S. federal income tax on our taxable income at the corporate tax rate, and would likely be liable for state income tax at varying rates. Distributions to our unitholders would generally be taxed again as corporate distributions, and no income, gains, losses, deductions, or credits would flow through to our unitholders. Because taxes would be imposed upon us as a corporation, our cash available 53 Table of Contents for distribution to our unitholders would be substantially reduced. Therefore, our treatment as a corporation would result in a material reduction in the anticipated cash flow and after-tax return to our unitholders, likely causing a substantial reduction in the value of our common units. ​ At the state level, several states have been evaluating ways to subject partnerships to entity-level taxation through the imposition of state income, franchise, or other forms of taxation. If any state were to impose a tax upon us as an entity, the cash available for distribution to you would be reduced and the value of our units could be negatively impacted. ​ The tax treatment of publicly traded partnerships or an investment in our units could be subject to potential legislative, judicial or administrative changes or differing interpretations, possibly applied on a retroactive basis. ​ The present U.S. federal income tax treatment of publicly traded partnerships, including us, or an investment in our common units may be modified by administrative, legislative or judicial changes or differing interpretations at any time. Members of Congress have frequently proposed and considered substantive changes to the existing U.S. federal income tax laws that would affect publicly traded partnerships, including proposals that would eliminate our ability to qualify for partnership tax treatment. Recent proposals have provided for the expansion of the qualifying income exception for publicly traded partnerships in certain circumstances and other proposals have provided for the total elimination of the qualifying income exception upon which we rely for our partnership tax treatment. In addition, the Treasury Department has issued, and in the future may issue, regulations interpreting those laws that affect publicly traded partnerships. There can be no assurance that there will not be further changes to U.S. federal income tax laws or the Treasury Department's interpretation of the qualifying income rules in a manner that could impact our ability to qualify as a partnership in the future. ​ Any modification to the U.S. federal income tax laws and the interpretations thereof may or may not be applied retroactively and could make it more difficult or impossible for us to meet the exception for certain publicly traded partnerships to be treated as partnerships for U.S. federal income tax purposes. We are unable to predict whether any changes or other proposals will ultimately be enacted. Any similar or future legislative changes could negatively impact the value of an investment in our common units. You are urged to consult with your own tax advisor with respect to the status of regulatory or administrative developments and proposals and their potential effect on your investment in our common units. ​ If the IRS were to contest the U.S. federal income tax positions we take, it may adversely impact the market for our common units, and the costs of any such contest would reduce cash available for distribution to our unitholders. ​ We have not requested a ruling from the IRS with respect to our treatment as a partnership for U.S. federal income tax purposes. The IRS may adopt positions that differ from the positions that we take. It may be necessary to resort to administrative or court proceedings to sustain some or all of the positions we take. A court may not agree with some or all of the positions we take. Any contest with the IRS may materially and adversely impact the market for our common units and the price at which they trade. Moreover, the costs of any contest between us and the IRS will result in a reduction in our cash available for distribution to our unitholders and thus will be borne indirectly by our unitholders. ​ If the IRS makes audit adjustments to our income tax returns for tax years beginning after December 31, 2017, it (and some states) may assess and collect any taxes (including any applicable penalties and interest) resulting from such audit adjustments directly from us, in which case our cash available for distribution to our unitholders could be reduced and our current and former unitholders may be required to indemnify us for any taxes (including any applicable penalties and interest) resulting from such audit adjustments that were paid on such unitholders' behalf. ​ Pursuant to the Bipartisan Budget Act of 2015, for tax years beginning after December 31, 2017, if the IRS makes audit adjustments to our income tax returns, it (and some states) may assess and collect any taxes (including any applicable penalties and interest) resulting from such audit adjustments directly from us. To the extent possible under these rules, our general partner may elect to either pay the taxes (including any applicable penalties and interest) directly to the IRS or, if we are eligible, issue a revised information statement to each unitholder and former unitholder with respect to an audited and adjusted return. Although our general partner may elect to have our unitholders and former unitholders take such audit adjustment into account and pay any resulting taxes (including applicable penalties and interest) in accordance with their interests in us during the tax year under audit, there can be no assurance that such election will be practical, permissible or effective in all circumstances. As a result, our current unitholders may bear some or all of the tax liability resulting from such audit adjustment, even if such unitholders did not own units in us during the tax year under audit. If, as a result of 54 Table of Contents any such audit adjustment, we are required to pay taxes, penalties and interest, our cash available for distribution to our unitholders might be substantially reduced and our current and former unitholders may be required to indemnify us for any taxes (including any applicable penalties and interest) resulting from such audit adjustments that were paid on such unitholders' behalf. These rules are not applicable for tax years beginning on or prior to December 31, 2017. ​ Our unitholders are required to pay taxes on their share of our income even if they do not receive any cash distributions from us. ​ Our unitholders are required to pay any U.S. federal income taxes and, in some cases, state and local income taxes, on their share of our taxable income whether or not they receive cash distributions from us. Our unitholders may not receive cash distributions from us equal to their share of our taxable income or even equal to the actual tax liability that results from that income. ​ Tax gain or loss on the disposition of our common units could be more or less than expected. ​ If a unitholder sells units, the unitholder will recognize a gain or loss equal to the difference between the amount realized and that unitholder's tax basis in those common units. Because distributions in excess of a unitholder's allocable share of our net taxable income decrease such unitholder's tax basis in its units, the amount, if any, of such prior excess distributions with respect to the units a unitholder sells will, in effect, become taxable income to a unitholder if it sells such units at a price greater than its tax basis in those units, even if the price such unitholder receives is less than its original cost. In addition, because the amount realized includes a unitholder's share of our nonrecourse liabilities, if a unitholder sells its units, a unitholder may incur a tax liability in excess of the amount of cash received from the sale. ​ A substantial portion of the amount realized from a unitholder's sale of our units, whether or not representing gain, may be taxed as ordinary income to such unitholder due to potential recapture items, including depreciation recapture. Thus, a unitholder may recognize both ordinary income and capital loss from the sale of units if the amount realized on a sale of such units is less than such unitholder's adjusted basis in the units. Net capital loss may only offset capital gains and, in the case of individuals, up to $3,000 of ordinary income per year. In the taxable period in which a unitholder sells its units, such unitholder may recognize ordinary income from our allocations of income and gain to such unitholder prior to the sale and from recapture items that generally cannot be offset by any capital loss recognized upon the sale of units. ​ Unitholders may be subject to limitation on their ability to deduct interest expense incurred by us. ​ In general, we are entitled to a deduction for interest paid or accrued on indebtedness properly allocable to our trade or business during our taxable year. However, our deduction for "business interest" is limited to the sum of our business interest income and 30% of our "adjusted taxable income." For the purposes of this limitation, our adjusted taxable income is computed without regard to any business interest expense or business interest income. If our "business interest" is subject to limitation under these rules, our unitholders will be limited in their ability to deduct their share of any interest expense that has been allocated to them. As a result, unitholders may be subject to limitation on their ability to deduct interest expense incurred by us. ​ Tax-exempt entities face unique tax issues from owning our common units that may result in adverse tax consequences to them. ​ Investment in our common units by tax-exempt entities, such as employee benefit plans and IRAs raises issues unique to them. For example, virtually all of our income allocated to organizations that are exempt from U.S. federal income tax, including IRAs and other retirement plans, will be unrelated business taxable income and will be taxable to them. Additionally, all or part of any gain recognized by such tax-exempt organization upon a sale or other disposition of our units may be unrelated business taxable income and may be taxable to them. Tax-exempt entities should consult a tax advisor before investing in our common units. ​ Non-U.S. unitholders will be subject to U.S. taxes and withholding with respect to their income and gain from owning our units. ​ Non-U.S. unitholders are generally taxed and subject to income tax filing requirements by the United States on income effectively connected with a U.S. trade or business. Income allocated to our unitholders and any gain from the sale of our units will generally be considered to be "effectively connected" with a U.S. trade or business. As a result, distributions to 55 Table of Contents a non-U.S. unitholder will be subject to withholding at the highest applicable effective tax rate and a non-U.S. unitholder who sells or otherwise disposes of a unit will also be subject to U.S. federal income tax on the gain realized from the sale or disposition of that unit. In addition to the withholding tax imposed on distributions of effectively connected income, distributions to a non-U.S. unitholder will also be subject to a 10% withholding tax on the amount of any distribution in excess of our cumulative net income. As we do not compute our cumulative net income for such purposes due to the complexity of the calculation and lack of clarity in how it would apply to us, we intend to treat all of our distributions as being in excess of our cumulative net income for such purposes and subject to such 10% withholding tax. Accordingly, distributions to a non-U.S. unitholder will be subject to a combined withholding tax rate equal to the sum of the highest applicable effective tax rate and 10%. ​ Moreover, the transferee of an interest in a partnership that is engaged in a U.S. trade or business is generally required to withhold 10% of the "amount realized" by the transferor unless the transferor certifies that it is not a foreign person. While the determination of a partner's "amount realized" generally includes any decrease of a partner's share of the partnership's liabilities, the Treasury regulations provide that the "amount realized" on a transfer of an interest in a publicly traded partnership, such as our common units, will generally be the amount of gross proceeds paid to the broker effecting the applicable transfer on behalf of the transferor, and thus will be determined without regard to any decrease in that partner's share of a publicly traded partnership's liabilities. For a transfer of interests in a publicly traded partnership that is effected through a broker on or after January 1, 2023, the obligation to withhold is imposed on the transferor's broker. Current and prospective non-U.S. unitholders should consult their tax advisors regarding the impact of these rules on an investment in our common units. ​ We treat each purchaser of our common units as having the same tax benefits without regard to the common units actually purchased. The IRS may challenge this treatment, which could adversely affect the value of our common units. ​ Because we cannot match transferors and transferees of common units, we have adopted certain methods for allocating depreciation and amortization deductions that may not conform to all aspects of existing Treasury Regulations. A successful IRS challenge to the use of these methods could adversely affect the amount of tax benefits available to our unitholders. It also could affect the timing of these tax benefits or the amount of gain from any sale of common units and could have a negative impact on the value of our units or result in audit adjustments to a unitholder's tax returns. ​ We generally prorate our items of income, gain, loss and deduction between transferors and transferees of our units each month based on the ownership of our units on the first day of each month, instead of on the basis of the date a particular unit is transferred. The IRS may challenge this treatment, which could change the allocation of items of income, gain, loss and deduction among our unitholders. ​ We generally prorate our items of income, gain, loss and deduction between transferors and transferees of our units each month based on the ownership of our units on the first day of each month, instead of on the basis of the date a particular unit is transferred. Similarly, we generally allocate (i) certain deductions for depreciation of capital additions, (ii) gain or loss realized on a sale or other disposition of our assets, and (iii) in the discretion of the general partner, any other extraordinary item of income, gain, loss or deduction based on ownership on the Allocation Date. Treasury Regulations allow a similar monthly simplifying convention, but such regulations do not specifically authorize all aspects of our proration method. If the IRS were to challenge our proration method, we may be required to change the allocation of items of income, gain, loss and deduction among our unitholders. ​ A unitholder whose units are the subject of a securities loan (e.g., a loan to a " short seller " to cover a short sale of units) may be considered as having disposed of those units. If so, such unitholder would no longer be treated for tax purposes as a partner with respect to those units during the period of the loan and may recognize gain or loss from the disposition. ​ Because there are no specific rules governing the U.S. federal income tax consequence of loaning a partnership interest, a unitholder whose units are the subject of a securities loan may be considered as having disposed of the loaned units. In that case, the unitholder may no longer be treated for tax purposes as a partner with respect to those units during the period of the loan to the short seller and the unitholder may recognize gain or loss from such disposition. Moreover, during the period of the loan, any of our income, gain, loss or deduction with respect to those units may not be reportable by the unitholder and any cash distributions received by the unitholder as to those units could be fully taxable as ordinary income. Unitholders desiring to assure their status as partners and avoid the risk of gain recognition from a securities loan are urged 56 Table of Contents to consult a tax advisor to determine whether it is advisable to modify any applicable brokerage account agreements to prohibit their brokers from borrowing their units. ​ Certain U.S. federal income tax deductions currently available with respect to coal mining and production may be eliminated as a result of future legislation. ​ In past years, members of the U.S. Congress have indicated a desire to eliminate certain key U.S. federal income tax provisions currently applicable to coal companies, including the percentage depletion allowance with respect to coal properties. Elimination of those provisions would not impact our financial statements or results of operations. However, elimination of such provisions could result in unfavorable tax consequences for our unitholders and, as a result, could negatively impact our unit price. ​ Our unitholders will likely be subject to state and local taxes and income tax return filing requirements in jurisdictions where they do not live as a result of investing in our common units. ​ In addition to U.S. federal income taxes, our unitholders may be subject to other taxes, such as state and local income taxes, unincorporated business taxes and estate, inheritance or intangible taxes that are imposed by the various jurisdictions in which we conduct business or own property now or in the future, even if they do not live in any of those jurisdictions. Our unitholders will likely be required to file state and local income tax returns and pay state and local income taxes in some or all of these various jurisdictions. Further, our unitholders may be subject to penalties for failure to comply with those requirements. ​ We currently own assets and conduct business in multiple states that currently impose a personal income tax on individuals, corporations and other entities. As we make acquisitions or expand our business, we may own assets or conduct business in additional states that impose a personal income tax. It is our unitholders' responsibility to file all U.S. federal, foreign, state, and local tax returns and pay any taxes due in these jurisdictions. Unitholders should consult with their own tax advisors regarding the filing of such tax returns, the payment of such taxes, and the deductibility of any taxes paid. ​ ITEM 1B. UNRESOLVED STAFF COMMENTS ​ None. ​ ITEM 1C. CYBERSECURITY ​ Description of Processes for Assessing, Identifying, and Managing Cybersecurity Risks ​ We operate in an increasingly interconnected digital landscape and we recognize the importance of assessing, identifying, and managing material risks from cybersecurity threats. In the normal course of business, we may collect and store certain sensitive information, including proprietary and confidential business information, intellectual property, sensitive third-party information, employee information and personal information. We rely on information systems for the management of this information in addition to our management of business processes including inventory, payment of obligations, collection of cash, human capital management, financial tools and other processes and procedures. Our ability to manage our business effectively depends on the reliability and capacity of these systems. We seek to address these risks by safeguarding assets, data, and operations through the cybersecurity risk management processes described below: ​ Risk Assessment: ​ Regular assessments are conducted across our systems, networks, and data infrastructure to identify potential cybersecurity threats and vulnerabilities. These assessments include penetration testing, vulnerability scanning, and red teaming exercises conducted by third-party service providers, which help us to evaluate the likelihood and potential impact of cybersecurity incidents. Feedback from these assessments is incorporated into our systems and procedures through upgrades intended to further improve our security posture. ​ 57 Table of Contents Incident Identification and Response: ​ A monitoring and detection system has been implemented to help identify cybersecurity incidents. The IT Security Department is tasked with monitoring certain network activities, logs, and system behavior, leveraging threat detection technologies. In the event of any breach or cybersecurity incident, we have an incident response plan that is designed to follow industry best practices and aligns with legal and regulatory requirements. This plan is designed to provide for immediate action to contain the incident, mitigate the impact, and restore normal operations efficiently. ​ Cybersecurity Training and Awareness: ​ Cybersecurity awareness among our employees is promoted with regular training and awareness programs. Employees receive training on recognizing and reporting potential cybersecurity threats, best practices for data protection, and adhering to cybersecurity policies and procedures. Additionally, periodic simulated phishing exercises are conducted to enhance employee readiness in identifying and mitigating phishing attacks. ​ Access Controls: ​ Access control policies have been implemented to limit unauthorized access to sensitive information and we seek to maintain and monitor critical systems. Multi-factor authentication is used for remote access, use of privileged accounts and access to critical systems. ​ Encryption and Data Protection: ​ Encryption methods are used to protect sensitive data in transit and at rest. This includes the encryption of customer data, financial information, and other confidential data. ​ The above cybersecurity risk management processes are integrated into the Partnership's overall risk management program. Cybersecurity threats are understood to be dynamic and intersect with various other enterprise risks. As such, cybersecurity is considered as an important component of our enterprise-wide risk management approach. We have assembled a Cybersecurity Steering Committee comprised of IT management, cybersecurity specialists, and representatives of business management, including the CTO and internal legal counsel. The Cybersecurity Steering Committee reviews information security policies and cybersecurity risks in conjunction with other operational, financial, and strategic risks to ensure alignment with our business objectives. The Cybersecurity Steering Committee convenes regularly to review and monitor the Partnership’s programs for the prevention, detection, mitigation, and remediation of cybersecurity incidents. The Cybersecurity Steering Committee receives reports on security incidents, threat intelligence, and vulnerability assessments from our IT Security Department. ​ The Cybersecurity Steering Committee regularly reports to the CFO through the CTO and reports annually on cybersecurity to the Audit Committee during a scheduled meeting. These reports include, as appropriate, updates on the current cybersecurity landscape, incident trends, and any significant developments that may impact the Partnership's security posture. ​ To enhance the effectiveness of our cybersecurity program, we periodically engage external assessors, consultants, and auditors. These third-party service providers conduct independent evaluations of our cybersecurity measures, helping to identify areas for improvement and adherence to industry standards and best practices. ​ Our IT Security Department recognizes that third-party service providers may introduce cybersecurity risks to our organization. In an effort to mitigate these risks, we have implemented a process designed to assess and oversee the cybersecurity practices of our vendors. Before engaging with any third-party cybersecurity service provider, we conduct due diligence to evaluate their cybersecurity capabilities. Additionally, we include cybersecurity requirements in our contracts with these providers, requiring them to adhere to certain cybersecurity standards and protocols. ​ Impact of Risks from Cybersecurity Threats ​ During 2023 and through the date of this Annual Report on Form 10-K, though the Partnership and our service providers may have experienced cybersecurity incidents, we are not aware of any cybersecurity threats, including as a 58 Table of Contents result of any previous cybersecurity incidents, that have materially affected or are reasonably likely to materially affect the Partnership, including our business strategy, result of operations, or financial condition. However, we acknowledge that cybersecurity threats are continually evolving, and the possibility of future cybersecurity incidents remains. Our IT Security Department aims to monitor and assess these risks to maintain the security and continuity of our operations. Despite the implementation of our cybersecurity programs, our security measures cannot guarantee that a significant cyberattack will not occur. A successful attack on our IT systems could have significant consequences to our business. While we devote resources to our security measures to protect our systems and information, these measures cannot provide absolute security. Please see "Item 1A. Risk Factors" for additional information about the risks to our business associated with a breach or compromise to our information technology systems. ​ Board of Directors' Oversight of Risks from Cybersecurity Threats ​ The Board of Directors oversees risks from cybersecurity threats. Recognizing the importance of cybersecurity to the success and resilience of our business, the Board considers cybersecurity to be an important aspect of corporate governance. To facilitate effective oversight, the Audit Committee and the Board of Directors hold discussions with management, including the CTO on cybersecurity risks, incident trends, and the effectiveness of cybersecurity measures annually and as needed during both scheduled and special meetings. If new material cybersecurity risks arise, the Board of Directors and the Audit Committee are informed through regular discussions between the CFO and both the Chairman of the Board and the Audit Committee Chair. These discussions are then brought to the attention of the Board of Directors and Audit Committee at the next meeting. ​ Management's Role and Expertise ​ The CTO and the Cybersecurity Steering Committee are responsible for overseeing and executing our cybersecurity strategy, including the assessment and management of cybersecurity risks. The CTO reports directly to the CFO and maintains communication with the Audit Committee, the Board of Directors and the Cybersecurity Steering Committee with respect to information security and cybersecurity matters. ​ The CTO holds a Master of Business Administration from the University of Kentucky/University of Louisville's joint executive program and has an extensive background in information security, risk management, and incident response with over twenty years of varying information technology roles with increasing responsibility at both private and public companies. The CTO is supported by a dedicated team of cybersecurity professionals, each bringing diverse expertise in areas such as network security, data protection, and threat intelligence. ​ 59 Table of Contents ​ ITEM 2. PROPERTIES ​ COAL MINERAL RESOURCES AND RESERVES ​ Overview of Coal Properties ​ Our coal properties are located in the Illinois Basin and the Appalachia Basin. Our Illinois Basin properties are located in western Kentucky, southern Illinois, and southern Indiana. Our Appalachian properties are located in eastern Kentucky, Maryland, western Pennsylvania, and northern West Virginia. Mining operations on our coal properties consist of underground mines that produce bituminous coal that is sold to customers principally for electric power generation (thermal) and the production of steel (metallurgical). In addition to our coal mining operations, we also hold coal mineral interests that we lease/sublease to our operations or hold for lease/sublease to our operations or others. For a detailed overview of our coal mining operations and our coal royalty activities, please see "Item 1. Business—Coal Mining Operations" and "Item 1. Business—Mineral Interest Activities", respectively. ​ Evaluation and Review of Coal Mineral Resources and Reserves ​ Numerous uncertainties are inherent in estimating coal mineral resources and reserves, and the estimates are subject to change as additional information becomes available or circumstances change. Significant factors and assumptions related to the uncertainty in estimating coal mineral reserves and resources include: ​ ● geological and mining conditions, which may not be fully identified by available exploration data and/or differ from our experiences in areas where we currently mine; ● the percentage of coal in the ground ultimately recoverable; ● historical production from the area compared with production from other producing areas; ● the assumed effects of regulation and taxes by governmental agencies; ● future improvements in mining technology; and ● assumptions concerning future coal prices, operating costs, capital expenditures, severance and excise taxes, and development and reclamation costs. ​ Each of the factors which impacts reserve and resource estimation may vary considerably from the assumptions used in making the estimation and, as a result, the estimates in this report may not accurately reflect the actual coal reserves and resources. Actual production, revenues and expenditures with respect to the coal reserves will likely vary from the assumptions used in these estimates, and these variances may be material. Government regulations and other pressures may result in the closure of coal-fired electric generating plants earlier than assumed. Such changes would reduce the economic viability of our mining operations and could have a material adverse impact on our operations and financial results. ​ Under SEC rules, a mineral resource is a concentration or occurrence of material of economic interest in or on the Earth's crust in such form, grade or quality, and quantity that there are reasonable prospects for economic extraction. A mineral resource is a reasonable estimate of mineralization, taking into account relevant factors such as cut-off grade, likely mining dimensions, location or continuity that, with the assumed and justifiable technical and economic conditions, is likely to, in whole or in part, become economically extractable. A mineral reserve is an estimate of tonnage and grade or quality of indicated and measured mineral resources that, in the opinion of the qualified person, can be the basis of an economically viable project. More specifically, it is the economically mineable part of a measured or indicated mineral resource, which includes diluting materials and allowances for losses that may occur when the material is mined or extracted. ​ The coal mineral resource and reserve estimates included in this Annual Report on Form 10-K were prepared by an independent, qualified engineering firm, RESPEC. We provided RESPEC with property control, mine plans, production, revenue, costs, capital, and other information considered by RESPEC in making their estimates. As part of our internal controls, our geologists and engineers review the integrity, accuracy, and timeliness of the data provided to RESPEC that they considered in calculating their coal mineral resource and reserve estimates. We also review the geologic data, mining assumptions, and methodology used by RESPEC to estimate our coal mineral resources and reserves. Our geologists and engineers also met with RESPEC periodically during the year to discuss the assumptions and methods used in the coal mineral resource and reserve estimation process. 60 Table of Contents ​ RESPEC, an independent third-party engineering firm, does not own an interest in any of our properties and is not employed on a contingent basis. RESPEC prepared the initial TRS for each of our material mining properties. The TRSs will be updated when there are material changes to the coal mineral reserve or resource estimates. The most recent TRSs for our material mining operations are included as exhibits to our Annual Report on Form 10-K. ​ Summary of Coal Mineral Resources and Reserves ​ Coal Mineral Resources ​ Most of our coal properties designated as mineral resources are of thickness, quality, and mineability similar to that of the mineral reserves, and all are proximal to existing infrastructure such as power, water, transportation, facilities, etc. However, we have not completed pre-feasibility or feasibility studies with respect to our coal properties designated as mineral resources, as is required to convert the mineral resources into mineral reserves. There is no certainty that all or any part of the mineral resources will be converted into mineral reserves. ​ The following table sets forth our coal mineral resources, exclusive of coal mineral reserves, at December 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Heat ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Content (Btus ​ Pounds SO2 per MMBtu ​ Resource Classification ​ Ownership ​ ​ ​ Resources (tons in millions) per pound) <1.2 1.2-2.5 >2.5 Measured Indicated Combined Inferred Owned Leased Total ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Dotiki (KY) 12,100 — 2.3 73.7 51.2 24.8 76.0 — 27.6 48.4 76.0 ​ Henderson/Union (KY) 11,450 — 3.0 409.7 127.3 227.9 355.2 57.5 74.0 338.7 412.7 ​ River View (KY) 11,450 ​ — ​ — ​ 0.3 ​ — ​ — ​ — ​ 0.3 ​ — ​ 0.3 ​ 0.3 ​ Sebree South (KY) 11,750 — — 43.5 22.1 16.8 38.9 4.6 0.3 43.2 43.5 ​ Hamilton County (IL) 11,650 5.1 33.8 405.8 191.2 242.3 433.5 11.2 32.8 411.9 444.7 ​ Region Total ​ ​ 5.1 ​ 39.1 ​ 933.0 ​ 391.8 ​ 511.8 ​ 903.6 ​ 73.6 ​ 134.7 ​ 842.5 ​ 977.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Appalachian Basin ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mountain View (WV) 13,200 — 0.4 8.3 4.1 4.4 8.5 0.2 1.8 6.9 8.7 ​ Tunnel Ridge (WV) ​ 12,600 ​ — — 0.9 — 0.2 0.2 0.7 0.7 0.2 0.9 ​ Penn Ridge (PA) 12,500 — — 78.0 21.9 53.2 75.1 2.9 78.0 — 78.0 ​ Region Total ​ ​ — ​ 0.4 ​ 87.2 ​ 26.0 ​ 57.8 ​ 83.8 ​ 3.8 ​ 80.5 ​ 7.1 ​ 87.6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ ​ 5.1 ​ 39.5 ​ 1,020.2 ​ 417.8 ​ 569.6 ​ 987.4 ​ 77.4 ​ 215.2 ​ 849.6 ​ 1,064.8 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ % of Total ​ ​ ​ 0.5% ​ 3.7% ​ 95.8% ​ 39.2% ​ 53.5% ​ 92.7% ​ 7.3% ​ 20.2% ​ 79.8% ​ 100.0% ​ (1) Combined resources are defined as measured plus indicated resources. ​ At December 31, 2023, we had approximately 1.065 billion tons of coal mineral resources. Tonnages are reported on a clean recoverable basis with average long-term pricing based on available third-party forecasts and historical pricing adjusted for quality at the end of 2023 in a range from approximately $53 to $59 per short ton in the Illinois Basin and from approximately $62 to $119 per short ton in the Appalachian Basin, which are the prices used by RESPEC to estimate the amount of coal mineral resources. Coal sales prices vary based on coal quality, access to transportation, and other factors at each location. All resources are classified as underground mineable in the exploration stage. ​ Coal Mineral Reserves ​ Reserves are assigned to our active operations and are (1) currently in production, (2) economically viable, and (3) meet the other requirements to be considered reserves as defined by the SEC. ​ 61 Table of Contents The following table sets forth coal mineral reserve information, exclusive of the coal mineral resources above, at December 31, 2023, about our coal operations: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Heat ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Content (Btus ​ Pounds SO2 per MMBtu ​ Classification ​ Ownership ​ ​ ​ Reserves (tons in millions) per pound) <1.2 1.2-2.5 >2.5 Proven Probable Owned Leased Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Operations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrior (KY) 12,300 — — 50.0 39.5 10.5 13.0 37.0 50.0 ​ River View (KY) 11,450 — — 310.4 169.1 141.3 58.0 ​ 252.4 310.4 ​ Hamilton County (IL) 11,650 — — 119.8 54.5 65.3 20.3 ​ 99.5 119.8 ​ Gibson South (IN) 11,500 0.9 9.5 34.8 35.6 9.6 15.3 29.9 45.2 ​ Region Total ​ ​ 0.9 ​ 9.5 ​ 515.0 ​ 298.7 ​ 226.7 ​ 106.6 ​ 418.8 ​ 525.4 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Appalachian Basin Operations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ MC Mining (KY) 12,800 9.6 0.5 — 7.8 2.3 — 10.1 10.1 ​ Mountain View (WV) 13,200 — 4.4 5.1 9.1 0.4 — 9.5 9.5 ​ Tunnel Ridge (WV) 12,600 — — 118.2 64.5 53.7 11.7 106.5 118.2 ​ Region Total ​ ​ 9.6 ​ 4.9 ​ 123.3 ​ 81.4 ​ 56.4 ​ 11.7 ​ 126.1 ​ 137.8 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ ​ 10.5 ​ 14.4 ​ 638.3 ​ 380.1 ​ 283.1 ​ 118.3 ​ 544.9 ​ 663.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ % of Total ​ ​ ​ 1.6% ​ 2.2% ​ 96.2% ​ 57.3% ​ 42.7% ​ 17.8% ​ 82.2% ​ 100.0% ​ ​ On December 31, 2023, we had approximately 663.2 million tons of coal mineral reserves. Tonnages are reported on a clean recoverable basis with average long-term pricing based on available third-party forecasts and historical pricing adjusted for quality at the end of 2023 in a range from approximately $53 to $59 per short ton in the Illinois Basin and from approximately $62 to $119 per short ton in the Appalachian Basin, which are the prices used by RESPEC to estimate the amount of coal mineral reserves. Coal sales prices vary based on coal quality, access to transportation, and other factors at each location. All reserves are classified as underground mineable in the development or production stage. ​ Mining Operations ​ The following table sets forth production and other data about our mining operations: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Tons Produced ​ ​ ​ ​ Operations Location 2023 2022 2021 Transportation Equipment ​ ​ ​ (in millions) ​ ​ ​ ​ ​ Illinois Basin Operations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrior Kentucky 4.4 4.1 4.1 CSX, NS, PAL, truck, barge CM ​ River View Kentucky 9.9 10.2 9.9 Truck, barge CM ​ Hamilton County Illinois 5.6 4.7 4.9 CSX, EVW, NS, barge LW, CM ​ Gibson South Indiana 5.3 5.3 3.3 CSX, NS, truck, barge CM ​ Region Total ​ ​ 25.2 24.3 22.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Appalachian Basin Operations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ MC Mining/Excel Kentucky 1.2 1.5 1.3 CSX, truck, barge CM ​ Mountain View West Virginia 0.8 1.4 1.5 CSX, truck LW, CM ​ Tunnel Ridge West Virginia 7.7 8.3 7.2 CSX, NS, barge LW, CM ​ Region Total ​ ​ 9.7 11.2 10.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ TOTAL ​ ​ 34.9 35.5 32.2 ​ ​ ​ ​ ​ CSX - CSX Railroad EVW - Evansville Western Railroad NS - Norfolk Southern Railroad PAL - Paducah & Louisville Railroad CM - Continuous Miner LW - Longwall 62 Table of Contents ​ Individual Property Disclosures ​ We consider the following properties to be material based on multiple factors including, but not limited to, the property's contribution to our overall business and financial condition. Please see Coal Mineral Resources and Coal Mineral Reserves above for information about the coal mineral resources and reserves held by these material properties. In addition to the following information, TRSs for these material properties with additional information are included as exhibits to this Annual Report on Form 10-K. ​ Henderson/Union Resources ​ The Henderson/Union Resources are located in Henderson and Union counties, Kentucky at 37°44'30"N, -87°46'07"W and we currently have control in over 1,600 tracts encompassing over 127,000 acres. The property is controlled through both fee ownership and leases of the coal. The coal mineral resources are controlled by Alliance Resource Properties. The base leases are with private owners and WKY CoalPlay or its subsidiaries, which are related parties. See "Item 8. Financial Statements and Supplementary Data — Note 20 – Related-Party Transactions" for more information about our WKY CoalPlay transactions. These base leases generally provide for a term that can be extended until exhaustion of the leased coal. Local infrastructure is as follows: ​ Major Roads: Interstates 69 and US-60, Railroads: None, Airport: Evansville Regional Airport (EVV), Town: Morganfield, Docks: River View, Hamilton 1, UC Processing, on the Ohio River, Water: Local municipalities and mine sources, Electricity: Kentucky Utilities (KU), Personnel: Regional. ​ 63 Table of Contents ​ Description ​ The potential underground mine(s) would utilize room-and-pillar methods operating a heavy media, float/sink style preparation plant. Exploration continues as needed to fulfill possible permitting and development requirements. Multiple access points are available for development. Access is available from the active River View complex, which began production in 2009. All equipment, facilities, infrastructure, and underground development are in good working order and maintained to industry standards. Access at the Hamilton and UC Coal, LLC sites are considered "brownfield" developments. Though some facilities and permitting are in place, significant upgrades to existing infrastructure and new construction would be needed to bring them into good working order that meets industry standards. The property associated with Henderson/Union has no book value as of December 31, 2023 but does have outstanding advanced royalties with WKY CoalPlay or its subsidiaries. See "Item 8. Financial Statements and Supplementary Data — Note 20 – Related-Party Transactions" for more information about advanced royalties that Henderson/Union has with WKY CoalPlay. ​ Though there is geographic overlap between the Henderson/Union and River View properties, the resources and reserves of each are associated with different coal seams or, if in the same seam, are separated by existing mine works or geologic features into distinct areas. There is no overlap in the resource / reserve estimation. ​ History ​ The Henderson/Union property contains resources in three coal seams, the WKY11, the WKY7, and the WKY6. Island Creek operated mines in the area and controlled a portion of the property. Under a joint venture, Texas Gas Service also controlled a large interest in the mineral rights. Lastly, Peabody and Patriot operated mines in the area and controlled a portion of the reserves. We consolidated control of the property through multiple transactions from 2005 through 2015. Island Creek operated the Ohio #11 mine. Peabody and later Patriot operated the Camp complex and Highland #11 mine to the southeast and east. The WKY11 seam was mined at these locations. No mining has occurred on the property in the 64 Table of Contents WKY7 or WKY6 seams. In general, all drilling has shown highly consistent coal seams of mineable thickness and quality for the high-sulfur thermal utility market. ​ Encumbrances ​ Our credit facility is secured by, among other things, liens against certain Henderson/Union surface properties and coal leases. Documentation of such liens is of record in the Offices of the Henderson and Union County Clerks. Please read "Item 8. Financial Statements and Supplementary Data — Note 6 – Long-term Debt" for more information on our credit facility. ​ The KYDNR, DMP is responsible for the review and issuance of all permits relative to coal mining and reclamation activities, and financial assurance of comprehensive environmental protection performance standards related to surface and underground coal mining operations. In addition to state mining and reclamation laws, operators must comply with various federal laws relevant to mining. ​ Geology and Reserves ​ Henderson/Union contains coal resources in three seams ranging in depths from about 100 to 750 feet. The table below summarizes mineral resources as of December 31, 2023, using a cut off thickness of 4.00 feet: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quality, Washed, Dry Basis ​ % Recovery ​ Resources (1) Tons (in millions) Thickness (ft) % Ash % Sulfur Btu lbs. SO2 In-Seam ​ ​ ​ ​ ​ ​ ​ ​ ​ Henderson/Union ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Measured Mineral Resources 127.3 4.68 7.72 2.88 13,327 4.32 85.48 ​ Indicated Mineral Resources ​ 227.9 ​ 4.59 ​ 8.01 ​ 2.74 ​ 13,306 ​ 4.12 ​ 87.07 ​ Combined Mineral Resources ​ 355.2 ​ 4.62 ​ 7.90 ​ 2.79 ​ 13,314 ​ 4.19 ​ 86.50 ​ Inferred Mineral Resources 57.5 4.46 7.97 2.56 13,350 3.84 90.42 ​ ​ (1) See updated TRS for Henderson/Union at Exhibit 96.1 to this Annual Report 10-K reflecting the material change to resources during 2023. ​ River View Complex ​ The River View complex is located in Union County, Kentucky at 37°45'37"N, -87°56'42"W and currently has approximately 93,200 underground acres permitted. The complex is composed of the River View and Henderson County mines along with shared preparation, loadout, and other ancillary facilities. The complex is controlled through both fee ownership and leases of the coal. The coal mineral reserves are leased or held for lease to the River View complex almost exclusively by Alliance Resource Properties. The River View complex either owns or controls the surface properties upon which its facilities are located including the preparation plant, refuse areas, mine offices, conveyor systems, shafts and slopes. The base leases are with private owners and generally provide for a term that can be extended until exhaustion of the leased coal. Local infrastructure is as follows: ​ Major Roads: Interstates 69 and US-60, Railroads: None, Airport: Evansville Regional Airport (EVV), Town: Morganfield, Docks: River View on the Ohio River, Water: Union and Henderson County water districts and mine sources, Electricity: Kentucky Utilities (KU), Personnel: Regional. ​ 65 Table of Contents ​ Description ​ The underground mines are currently in production using room-and-pillar methods utilizing a heavy media, float/sink style preparation plant. Exploration continues as needed to fulfill mining and permitting requirements. The complex began production in 2009. All equipment, facilities, infrastructure, and underground development are in good working order and maintained to industry standards. Total book value of the property and any associated plant and equipment for the River View Complex as of December 31, 2023 was $312.7 million. ​ Though there is geographic overlap between the River View complex and the Henderson/Union properties, the reserves and resources of each are associated with different coal seams or, if in the same seam, are separated by existing mine works or geologic features into distinct areas. There is no overlap in the resource / reserve estimation. ​ History ​ Island Creek operated mines in the area and controlled a portion of the property. Under a joint venture, Texas Gas Service also controlled a large interest in the mineral rights. Lastly, Peabody and Patriot operated mines in the area and controlled a smaller portion of the reserves. We consolidated control of the property through multiple transactions from 2005 through 2015. Island Creek operated the Ohio #11 and Uniontown #9 mines to the west of River View. Island Creek also operated the Hamilton #1 and #2 mines to the southwest. Peabody and later Patriot operated the Camp mines and Highland mines adjacent to the complex. Both the WKY9 and WKY11 seams were mined at these locations. In general, all drilling has shown highly consistent coal seams of mineable thickness and quality for the high-sulfur thermal utility market. ​ 66 Table of Contents Encumbrances ​ Our credit facility is secured by, among other things, liens against certain River View complex surface properties and coal leases. Documentation of such liens is of record in the Office of the Union County Clerk. Please read "Item 8. Financial Statements and Supplementary Data—Note 6 – Long-term Debt" for more information on our credit facility. ​ Accounts receivable generated from the sale of coal mined from this property are collateral for our accounts receivable securitization facility, evidenced by financing statements of record in the Office of the Union County Clerk. Please read "Item 8. Financial Statements and Supplementary Data—Note 6 – Long-term Debt" for more information on our accounts receivable securitization facility. ​ The KYDNR, DMP is responsible for review and issuance of all permits relative to coal mining and reclamation activities, and financial assurance of comprehensive environmental protection performance standards related to surface and underground coal mining operations. In addition to state mining and reclamation laws, operators must comply with various federal laws relevant to mining. All applicable permits for underground mining, coal preparation and related facilities, and other incidental activities have been obtained and remain in good standing. ​ Geology and Reserves ​ The River View complex extracts coal underground from the West Kentucky No. 11 and No. 9 seams with depths ranging from 200 to 500 feet across the reserve. The table below summarizes mineral reserves as of December 31, 2023 using a cut off thickness of 4.00 feet: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quality, Washed, Dry Basis ​ % Recovery ​ Reserves Tons (in millions) Thickness (ft) % Ash % Sulfur Btu lbs. SO2 In-Seam ​ ​ ​ ​ ​ ​ ​ ​ ​ River View Complex ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Proven Mineral Reserves 169.1 4.69 8.08 3.20 13,191 4.85 87.40 ​ Probable Mineral Reserves 141.3 4.56 8.25 3.18 13,141 4.85 87.25 ​ Total Mineral Reserves ​ 310.4 ​ 4.63 8.16 ​ 3.19 ​ 13,168 ​ 4.85 ​ 87.33 ​ ​ Resources associated with the River View complex are included in the Coal Mineral Resources table above. ​ The River View complex had 204.7 million tons of coal mineral reserves at the end of 2022. The year over year reconciliation is as follows: ​ ​ ​ ​ ​ River View Complex Yearly Reserve Reconciliation (in millions) Tons as of December 31, 2022 204.7 Production ​ (9.9) ​ Mineral Acquisition / Deletion (1) ​ 115.2 ​ Normal Course Adjustments ​ 0.4 ​ Tons as of December 31, 2023 ​ 310.4 ​ ​ (1) See updated TRS for River View complex at Exhibit 96.2 to this Annual Report on Form 10-K reflecting the material change to reserves for 2023. ​ Normal course adjustments are associated with numerous slight changes in the geologic model. ​ Hamilton Mine ​ Hamilton, a longwall mine located in Hamilton County, Illinois at 38°10'12"N, -88°36'47"W, currently has approximately 23,000 underground acres and 1,300 surface acres permitted. The mine property is controlled through both fee ownership and leases of the coal. The coal mineral reserves and resources are leased or held for lease to Hamilton by Alliance WOR Properties, a subsidiary of Alliance Resource Properties. Hamilton either owns or controls the surface properties upon which its facilities are located including the preparation plant, refuse areas, mine offices, conveyor systems, shafts and slopes. The underlying base coal leases are with private owners and are comprised of a large number of leases originally taken by AMAX Coal Company and Old Ben in the mid to late 1970's and early, leases acquired by 67 Table of Contents Consolidation Coal Company in the late 1980's, and subsequent leases taken directly by White Oak Resources, LLC or affiliated companies and/or Alliance WOR Properties. Local infrastructure is as follows: ​ Major Roads: Interstates 64, Railroads: CSX and EVW, Airport: Evansville Regional Airport (EVV), Towns: McLeansboro and Mt. Vernon, Docks: Mount Vernon on the Ohio River, Water: Hamilton County Water District and mine sources, Electricity: Wayne-White Electric Co-op (WWEC), Personnel: Regional. ​ Description ​ The underground mine is currently in production using longwall and room-and-pillar methods utilizing a heavy media, float/sink style preparation plant. Exploration continues as needed to fulfill mining and permitting requirements. The mine began production in 2014. All equipment, facilities, infrastructure, and underground development are in good working order and maintained to industry standards. Total book value of the property and any associated plant and equipment for Hamilton as of December 31, 2023 was $332.4 million. ​ History ​ There were no previous operations on the Hamilton reserves property prior to our predecessor, White Oak Resources LLC, who began construction of the mine in 2011. In general, all drilling has shown highly consistent coal seams of mineable thickness and quality for the high-sulfur thermal utility market for the Herrin and Springfield seams. ​ 68 Table of Contents Encumbrances ​ Our credit facility is secured by, among other things, liens against certain Hamilton surface properties, coal leases and owned coal. Documentation of such liens is of record in the Office of the Hamilton County Clerk. Please read "Item 8. Financial Statements and Supplementary Data — Note 6 – Long-term Debt" for more information on our credit facility. ​ Certain leases originally acquired by Consolidation Coal Company are encumbered by an overriding royalty payable to Sustainable Conservation, Inc. in the amount of the greater of $0.25 per ton or 0.75% of the average sales realization price received per ton, which sums can be credited against approximately $481,000 previously paid to Sustainable Conservation, Inc. for the assignment of these leases. ​ The Illinois Department of Natural Resources, Land Reclamation Division is responsible for review and issuance of all permits relative to coal mining and reclamation activities, and financial assurance of comprehensive environmental protection performance standards related to surface and underground coal mining operations. In addition to state mining and reclamation laws, operators must comply with various federal laws relevant to mining. All applicable permits for underground mining, coal preparation and related facilities and other incidental activities have been obtained and remain in good standing. ​ Geology and Reserves ​ Hamilton extracts coal underground from the Herrin (Illinois No.6) seam with depths ranging from 900 to 1100 feet across the reserve. The table below summarizes mineral reserves as of December 31, 2023 using a cut off thickness of 4.00 feet: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quality, Washed, Dry Basis ​ % Recovery ​ Reserves Tons (in millions) Thickness (ft) % Ash % Sulfur Btu lbs. SO2 In-Seam ​ ​ ​ ​ ​ ​ ​ ​ ​ Hamilton County ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Proven Mineral Reserves 54.5 6.38 8.07 2.82 13,414 4.21 86.65 ​ Probable Mineral Reserves 65.3 6.60 7.98 2.85 13,422 4.24 86.77 ​ Total Mineral Reserves ​ 119.8 ​ 6.50 8.02 ​ 2.83 ​ 13,419 ​ 4.23 ​ 86.71 ​ ​ Resources associated with Hamilton County are included in the Coal Mineral Resources table above. ​ The Hamilton mine had 125.9 million tons of coal mineral reserves at the end of 2022. The year over year reconciliation is as follows: ​ ​ ​ ​ ​ Hamilton County Yearly Reserve Reconciliation (in millions) Tons as of December 31, 2022 125.9 Production ​ (5.6) ​ Mineral Acquisition / Deletion ​ 4.1 ​ Mine Plan Adjustment ​ (4.9) ​ Normal Course Adjustments ​ 0.3 ​ Tons as of December 31, 2023 ​ 119.8 ​ ​ Normal course adjustments are associated with numerous slight changes in the geologic model. ​ Gibson South Mine ​ Gibson South is located in Gibson County, Indiana at 38°18'22"N, 87°42'30"W and currently has approximately 23,350 underground acres permitted. The mine property is controlled through both fee ownership and leases of the coal. Leases generally have an initial term with automatic extensions for as long as mining operations are conducted within a described area. Local infrastructure is as follows: ​ Major Roads: Interstates 69 and 64, Railroads: CSX and NS, Airport: Evansville Regional Airport (EVV), Town: Princeton, Docks: Mount Vernon on the Ohio River, 69 Table of Contents Water: Gibson Water, Inc. and well water, Electricity: Western Indiana Energy REMC, Personnel: Regional. Description ​ The underground mine is currently in production using room-and-pillar methods utilizing a heavy media, float/sink style preparation plant. Exploration continues as needed to fulfill mining and permitting requirements. The mine began production in 2014. All equipment, facilities, infrastructure, and underground development are in good working order and maintained to industry standards. Total book value of the property and any associated plant and equipment for Gibson South as of December 31, 2023 was $117.0 million. ​ History ​ In November 1997, pursuant to (a) Assignment of Underground Coal Leases, (b) Partial Assignment of Underground Coal Leases and (c) Special Corporate Warranty Deed, Old Ben conveyed to MAPCO Land & Development Corporation various coal leases and fee coal interests within a large property boundary located in Gibson County, Indiana. MAPCO Land & Development Corporation changed its name to MAPCO Coal Land & Development Corporation, and MAPCO Coal Land & Development Corporation merged into Alliance Properties effective August 4, 1999. ​ After the original Old Ben acquisition, Alliance Properties and Gibson continued to acquire additional coal leases and fee coal interests in the area. In addition, beginning in or around 2006, the leases originally acquired from Old Ben began to expire by their terms, and Alliance Properties/Gibson began a program of either amending the expiring leases or entering into new, direct leases with the coal owners. Alliance Properties merged into Gibson on February 19, 2018. ​ 70 Table of Contents The King's Mine operated to the east and the Wabash Mine operated to the west of the reserve area. In general, all drilling has shown a highly consistent coal seam of mineable thickness and quality for the high-sulfur thermal utility market. ​ Encumbrances ​ Our credit facility is secured by, among other things, liens against certain Gibson surface properties, coal leases and owned coal. Documentation of such liens is of record in the Office of the Recorder of Gibson County, Indiana. Please read "Item 8. Financial Statements and Supplementary Data—Note 6 – Long-term Debt" for more information on our credit facility. ​ Accounts receivable generated from the sale of coal mined from this property are collateral for our accounts receivable securitization facility, evidenced by financing statements of record in the Office of the Recorder of Gibson County, Indiana. Please read "Item 8. Financial Statements and Supplementary Data — Note 6 – Long-term Debt" for more information on our accounts receivable securitization facility. ​ The Indiana Department of Natural Resources, Division of Reclamation is responsible for oversight of active coal mining and reclamation activities, and financial assurance of comprehensive environmental protection performance standards related to surface and underground coal mining operations. In addition to state mining and reclamation laws, operators must comply with various federal laws relevant to mining. All applicable permits for underground mining, coal preparation, and related facilities and other incidental activities have been obtained and remain in good standing. ​ Geology and Reserves ​ Gibson South extracts coal underground from the Springfield (Indiana No.5) seam with depths ranging from 450 to 650 feet across the reserve. The table below summarizes mineral reserves as of December 31, 2023 using a cut off thickness of 4.00 feet: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quality, Washed, Dry Basis ​ % Recovery ​ Reserves Tons (in millions) Thickness (ft) % Ash % Sulfur Btu lbs. SO2 In-Seam ​ ​ ​ ​ ​ ​ ​ ​ ​ Gibson South ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Proven Mineral Reserves 35.6 5.96 7.13 2.00 13,477 2.97 94.81 ​ Probable Mineral Reserves 9.6 5.33 8.15 2.51 13,322 3.77 92.82 ​ Total Mineral Reserves ​ 45.2 ​ 5.81 7.34 ​ 2.11 ​ 13,444 ​ 3.14 ​ 94.37 ​ ​ Resources associated with Gibson South are included in the Coal Mineral Resources table above. ​ The Gibson South mine had 49.0 million tons of coal mineral reserves at the end of 2022. The year over year reconciliation is as follows: ​ ​ ​ ​ ​ Gibson South Yearly Reserve Reconciliation (in millions) Tons as of December 31, 2022 49.0 Production ​ (5.3) ​ Mineral Acquisition / Deletion ​ 1.5 ​ Tons as of December 31, 2023 ​ 45.2 ​ ​ Normal course adjustments are associated with numerous slight changes in the geologic model. ​ 71 Table of Contents Tunnel Ridge Mine ​ Tunnel Ridge, located at 40°09'17" N, -80°39'26"W, is an underground longwall mine in the Pittsburgh No. 8 seam of coal, and currently has approximately 22,345 underground acres permitted. The mine property is controlled through both fee ownership and leases of the coal. The coal mined and to be mined by Tunnel Ridge is leased from the Joseph W. Craft III Foundation, the Kathleen S. Craft Foundation, Alliance Resource Properties and third parties. Please read "Item 8. Financial Statements and Supplemental Data - Note 20 – Related-Party Transactions" for additional information on related-party leases. Tunnel Ridge either owns or controls the surface properties upon which its facilities are located, including the preparation plant, refuse areas, mine offices, conveyor systems, shafts and slopes. Local infrastructure is as follows: ​ Major Roads: Interstate 70, Railroads: None, Airport: Pittsburgh International Airport (PIT), Town: Wheeling, Docks: Tunnel Ridge on the Ohio River, Water: Municipal water districts and mine sources, Electricity: American Electric Power (AEP), West Penn Power (WPP) Personnel: Regional. Description ​ The underground mine is currently in production using longwall and room-and-pillar methods utilizing a heavy media, float/sink style preparation plant. Exploration continues as needed to fulfill mining and permitting requirements. The mine began production in 2010. All equipment, facilities, infrastructure, and underground development are in good working order and maintained to industry standards. Total book value of the property and any associated plant and equipment for Tunnel Ridge as of December 31, 2023 was $301.7 million. 72 Table of Contents ​ History ​ Valley Camp Coal Company operated mines on the property prior to Tunnel Ridge's operations. In general, all drilling has shown a highly consistent coal seam of mineable thickness and quality for the high-sulfur thermal utility market. ​ Encumbrances ​ Our credit facility is secured by, among other things, liens against certain Tunnel Ridge surface properties, coal leases and owned coal. Documentation of such liens is of record in the Office of the County Commission of Ohio County, West Virginia and the Office of the Recorder of Deeds of Washington County, Pennsylvania. Please read "Item 8. Financial Statements and Supplementary Data — Note 6 – Long-term Debt" for more information on our credit facility. ​ Accounts receivable generated from the sale of coal mined from this property are collateral for our accounts receivable securitization facility, evidenced by financing statements of record in the Office of the County Commission of Ohio County, West Virginia and the Office of the Recorder of Deeds of Washington County, Pennsylvania. Please read "Item 8. Financial Statements and Supplementary Data — Note 6 – Long-term Debt" for more information on our accounts receivable securitization facility. ​ Tunnel Ridge is located on the West Virginia / Pennsylvania State boundary, operating in each state. As such, regulatory requirements must be met pertaining to mining facilities located in each state. ​ For operations in West Virginia, the WVDEP is the regulatory authority over mining activities. Within the WVDEP, the Division of Mining and Reclamation is responsible for review and issuance of all permits relative to coal mining and reclamation activities, and financial assurance of comprehensive environmental protection performance standards related to surface and underground coal mining operations. ​ For operations in Pennsylvania, the PADEP is the regulatory authority over mining activities. Within the PADEP, the Bureau of District Mining Operations is responsible for review and issuance of all permits relative to coal mining and reclamation activities, and financial assurance of comprehensive environmental protection performance standards related to surface and underground coal mining operations. ​ Geology and Reserves ​ Tunnel Ridge extracts coal underground from the Pittsburgh No.8 seam with depths ranging from 300 to 975 feet across the reserve. The table below summarizes mineral reserves as of December 31, 2023 using a cut off thickness of 4.00 feet: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quality, Washed, Dry Basis ​ % Recovery ​ Reserves Tons (in millions) Thickness (ft) % Ash % Sulfur Btu lbs. SO2 In-Seam ​ ​ ​ ​ ​ ​ ​ ​ ​ Tunnel Ridge ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Proven Mineral Reserves 64.5 7.12 7.92 3.10 13,711 4.52 67.88 ​ Probable Mineral Reserves 53.7 7.26 8.30 3.49 13,618 5.13 68.06 ​ Total Mineral Reserves ​ 118.2 ​ 7.18 8.09 ​ 3.28 ​ 13,669 ​ 4.79 ​ 67.96 ​ ​ Resources associated with Tunnel Ridge are included in the Coal Mineral Resources table above. ​ 73 Table of Contents The Tunnel Ridge mine had 120.0 million tons of coal mineral reserves at the end of 2022. The year over year reconciliation is as follows: ​ ​ ​ ​ ​ Tunnel Ridge Yearly Reserve Reconciliation (in millions) Tons as of December 31, 2022 120.0 Production ​ (7.7) ​ Mineral Acquisition / Deletion ​ (1.2) ​ Mine Plan Adjustment ​ 6.8 ​ Normal Course Adjustments ​ 0.3 ​ Tons as of December 31, 2023 ​ 118.2 ​ ​ OIL & GAS RESERVES ​ Summary of Oil & Gas Reserves ​ Our mineral interests are primarily located in three basins, which are also our areas of focus for future development. These include the Permian (Delaware and Midland), Anadarko (SCOOP/STACK) and Williston (Bakken) Basins. At December 31, 2023, we had 49,794 developed and undeveloped net acres held at a weighted average royalty of 17.0%. Our net acres standardized to 1/8th royalty equates to 67,745 net royalty acres, including 3,969 net royalty acres owned through our equity interest in AllDale III. ​ The following table presents our estimated net proved oil & gas reserves, including our share of reserves attributable to our equity interest in AllDale III, as of December 31, 2023 based on the reserve report prepared by our internal engineering team and reserve information provided by AllDale III. The reserve report and reserve information have been prepared in accordance with the rules and regulations of the SEC. All of our proved reserves are located in the continental United States. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2023 ​ ​ Crude Oil Natural Gas Natural Gas Liquids Total ​ (MBbl) (MMcf) (MBbl) (MBOE) (2) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated proved developed reserves ​ ​ 7,754 ​ ​ 45,684 ​ ​ 5,485 ​ ​ 20,854 Estimated proved undeveloped reserves ​ ​ 1,599 ​ ​ 5,839 ​ ​ 868 ​ ​ 3,440 Total estimated proved reserves (1) ​ ​ 9,353 ​ ​ 51,523 ​ ​ 6,353 ​ ​ 24,294 (1) Proved reserves of approximately 1,780 MBOE were attributable to noncontrolling interests as of December 31, 2023. (2) Natural gas reserve volumes are converted to BOE based on a 6:1 ratio: 6 Mcf of natural gas converts to one BOE. ​ Estimates of reserves as of December 31, 2023 were prepared using product prices equal to the unweighted arithmetic average of the first-day-of-the-month market price for each month in the period from January through December 2023. The average realized product prices weighted by production over the remaining lives of the properties are $77.61/Bbl for oil, $1.55/Mcf of natural gas and $22.63 per barrel of NGL. These prices are adjusted for energy content, associated average differential and transportation deducts by producing area to arrive at the net realized prices by product. For 2023, NGL prices averaged approximately 33% of the posted oil prices during the course of the year with an additional $3.18/Bbl deducted for transportation costs. ​ The following table summarizes our changes in proved undeveloped reserves (in MBOE): ​ ​ ​ ​ ​ ​ Beginning balance, January 1, 2023* ​ ​ 3,795 ​ Acquisitions of proved undeveloped reserves ​ ​ 38 ​ Transfers of PUDs to estimated proved developed ​ ​ (1,448) ​ Extensions and discoveries ​ ​ 2,462 ​ Revisions of previous estimates ​ ​ (1,407) ​ Ending balance, December 31, 2023 ​ ​ 3,440 ​ * Recast to reflect the JC Resources Acquisition as if we, rather than JC Resources, acquired the mineral interests in 2019. Please see "Item 8. Financial Statement and Supplemental Data—Note 1 – Organization and Presentation and Note 3 – Acquisitions" for more information. 74 Table of Contents ​ As a mineral interest owner we have no transparency into or control over the Operators' investments and operational progress to convert PUDs to proved developed producing reserves. We do not incur any capital expenditures or lease operating expenses in connection with the development of our PUDs, which costs are borne entirely by the Operators. As a result, during the year ended December 31, 2023, we did not have any expenditures to convert PUDs to proved developed producing reserves. PUDs that have not been developed within two years of permitting are reviewed and removed from proved reserves as necessary. As of December 31, 2023, approximately 14.16% of our total proved reserves were classified as PUDs. ​ Evaluation and Review of Reserves ​ Numerous uncertainties are inherent in estimating reserve volumes and values, and the estimates are subject to change as additional information becomes available. The reserves actually recovered and the timing of production of the reserves may vary significantly from the original estimates. ​ Under SEC rules, proved reserves are those quantities of oil & gas, which, by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be economically producible–from a given date forward, from known reservoirs and under existing economic conditions, operating methods and government regulations–prior to the time at which contracts providing the right to operate expire, unless evidence indicates that renewal is reasonably certain, regardless of whether deterministic or probabilistic methods are used for the estimation. If deterministic methods are used, the SEC has defined reasonable certainty for proved reserves as a "high degree of confidence that the quantities will be recovered." All of our proved reserves as of December 31, 2023 were estimated using a deterministic method. The estimation of reserves involves two distinct determinations. The first determination results in the estimation of the quantities of recoverable oil & gas and the second determination results in the estimation of the uncertainty associated with those estimated quantities in accordance with the definitions established under SEC rules. The process of estimating the quantities of recoverable oil & gas reserves relies on the use of certain generally accepted analytical procedures. These analytical procedures fall into three broad categories or methods: ​ (1) performance-based methods, (2) volumetric-based methods and (3) analogy. ​ These methods may be used singularly or in combination by the reserve evaluator in the process of estimating the quantities of reserves. The proved reserves for our properties were estimated by performance methods, analogy or a combination of both methods. Performance methods include, but may not be limited to, decline curve analysis, which utilized extrapolations of available historical production data. The analogy method was used where there were inadequate historical performance data to establish a definitive trend and where the use of production performance data as a basis for the reserve estimates was considered to be inappropriate. ​ To estimate economically recoverable proved reserves and related future net cash flows, our engineering team considered many factors and assumptions, including the use of reservoir parameters derived from geological, geophysical and engineering data which cannot be measured directly, economic criteria based on current costs and the SEC pricing requirements and forecasts of future production rates. To establish reasonable certainty with respect to our estimated proved reserves, the technologies and economic data used in the estimation of our proved reserves included production and well test data, downhole completion information, geologic data, electrical logs, and radioactivity logs. ​ Excluding our share of proved reserves held by AllDale III, our 2023 year-end estimate of proved reserves were prepared by our internal engineering team. Our engineering team works to ensure the integrity, accuracy, and timeliness of the data used to calculate our estimated proved reserves. Our proved resource estimates were audited by CGA. Our engineering team met with CGA periodically during the period covered by the above referenced reserve report to discuss the assumptions and methods used in the reserve estimation process. Our engineering team provided historical information to CGA for our properties, such as oil & gas production, well test data, and realized commodity prices. Our engineering team also provided ownership interest information with respect to our properties. Our internal petroleum engineer, primarily responsible for overseeing the petroleum reserves preparation, has over 20 years of engineering and operations experience in the oil & gas sector and a Bachelor of Science in Petroleum Engineering. ​ The preparation of our proved reserve estimates are completed in accordance with our internal control procedures. These procedures, which are intended to ensure reliability of reserve estimations, include the following: 75 Table of Contents ​ ● review and verification of historical data, which is based on actual production as reported by the Operators; ● verification of property ownership by our land department; ● review of all our reported proved reserves semi-annually including the review of all significant reserve changes and proved undeveloped reserves additions by our internal petroleum engineer; ● internally prepared reserve estimates compared to reserves audit by CGA; ● review of changes in reserves semi-annually by our internal petroleum engineer and by senior management; and ● no employee ' s compensation is tied to the amount of reserves booked. ​ CGA, an independent third-party petroleum engineering firm, does not own an interest in any of our properties and is not employed on a contingent basis. When compared on a well-by-well basis, some of our estimates are greater and some are less than the CGA estimates. CGA is satisfied with our methods and procedures used to prepare the December 31, 2023 reserve estimates and future revenue, and noted nothing of an unusual nature that would cause CGA to take exception with the estimates, in the aggregate, prepared by us. CGA's audit report with the respect to our proved reserve estimates as of December 31, 2023 is included as an exhibit to this Annual Report on Form 10-K. ​ CGA was founded in 1961 and performs consulting petroleum engineering services under Texas Board of Professional Engineers Registration No. F-693. Within CGA, the technical person primarily responsible for auditing the estimates meets or exceed the education, training, and experience requirements set forth in the Standards Pertaining to the Estimating and Auditing of Oil and Gas Reserves Information promulgated by the Society of Petroleum Engineers and is proficient in judiciously applying industry-standard practices to engineering and geoscience evaluations as well as applying SEC and other industry reserves definitions and guidelines. ​ Acreage Concentration ​ Our mineral interests, which include both proved reserves discussed above and unproved reserves, are primarily located in three basins, which are also our areas of focus for future operator development. These include the Permian (Delaware and Midland), Anadarko (SCOOP/STACK) and Williston (Bakken) Basins. Below is a chart reflecting our gross, net mineral and net royalty acreage associated with our mineral interests in each of our primary basins as of December 31, 2023. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Developed Acreage ​ Undeveloped Acreage ​ Gross Net Mineral Net Royalty Gross Net Mineral Net Royalty Basin ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Permian Basin ​ ​ 378,510 ​ ​ 11,114 ​ ​ 14,894 ​ ​ 517,804 ​ ​ 15,204 ​ ​ 20,350 ​ Anadarko Basin ​ ​ 179,993 ​ ​ 6,489 ​ ​ 9,199 ​ ​ 295,884 ​ ​ 10,667 ​ ​ 15,112 ​ Williston Basin ​ ​ 153,772 ​ ​ 2,541 ​ ​ 3,363 ​ ​ 84,118 ​ ​ 1,390 ​ ​ 1,849 ​ Other ​ ​ 28,174 ​ ​ 1,027 ​ ​ 1,296 ​ ​ 37,363 ​ ​ 1,362 ​ ​ 1,682 ​ Total ​ ​ 740,449 ​ ​ 21,171 ​ ​ 28,752 ​ ​ 935,169 ​ ​ 28,623 ​ ​ 38,993 ​ ​ 76 Table of Contents Oil & Gas Production Prices and Production Costs ​ For the year ended December 31, 2023, 45.5% of our production and 79.4% of our oil & gas revenues were related to oil production and sales, respectively. The following table sets forth information regarding production of oil & gas including our equity investment in AllDale III and certain price and cost information for each of the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 ​ 2022* ​ 2021* Production: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Oil (MBbls) ​ ​ 1,462 ​ ​ 1,104 ​ ​ 929 ​ Natural gas (MMcf) ​ ​ 6,161 ​ ​ 5,226 ​ ​ 3,881 ​ Natural gas liquids (MBbls) ​ ​ 726 ​ ​ 541 ​ ​ 402 ​ BOE (MBbls) ​ ​ 3,215 ​ ​ 2,516 ​ ​ 1,978 ​ Average Realized Prices: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Oil (per Bbl) ​ $ 77.40 ​ $ 94.76 ​ $ 66.19 ​ Natural gas (per Mcf) ​ $ 2.03 ​ $ 6.29 ​ $ 3.86 ​ Natural gas liquids (per Bbl) ​ $ 23.15 ​ $ 38.53 ​ $ 28.58 ​ BOE (MBbls) ​ $ 44.32 ​ $ 62.94 ​ $ 44.47 ​ Unit cost per BOE: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Production and ad valorem taxes ​ $ 4.37 ​ $ 5.61 ​ $ 4.54 ​ * Recast to reflect the JC Resources Acquisition as if we, rather than JC Resources, acquired the mineral interests in 2019. Please see "Item 8. Financial Statement and Supplemental Data—Note 1 – Organization and Presentation and Note 3 – Acquisitions" for more information. ​ Productive Wells ​ As of December 31, 2023, 10,795 gross productive horizontal wells and 5,769 gross productive vertical wells were located on the acreage in which we have a mineral interest. Of our productive horizontal wells, 992 are considered natural gas wells, while the remaining 9,803 primarily produce oil. Productive wells consist of producing wells and wells capable of production, including natural gas wells awaiting pipeline connections to commence deliveries and oil wells awaiting connection to production facilities. We do not own any material working interests in any wells. Accordingly, we do not own any net wells. ​ Drilling Results ​ As a holder of mineral interests, we generally are not provided with information as to whether any wells drilled on the acreage associated with our mineral interests are classified as exploratory or as developmental wells. We are not aware of any dry holes drilled on the acreage associated with our mineral interests during the relevant period. ​ ​ ITEM 3. LEGAL PROCEEDINGS ​ From time to time, we are party to litigation matters incidental to the conduct of our business. It is the opinion of management that the ultimate resolution of our pending litigation matters will not have a material adverse effect on our financial condition, results of operation or liquidity. However, we cannot assure you that disputes or litigation will not arise or that we will be able to resolve any such future disputes or litigation in a satisfactory manner. The information under "General Litigation" and "Other" in "Item 8. Financial Statements and Supplementary Data—Note 21 – Commitments and Contingencies" is incorporated herein by this reference. ​ Litigation was initiated in November 2019 in the U.S. District Court for the Western District of Kentucky (Branson v. Webster County Coal, LLC et al.) against certain of our subsidiaries in which the plaintiffs allege violations of the Fair Labor Standards Act and state law due to alleged failure to compensate for time "donning" and "doffing" equipment and to account for certain bonuses in the calculation of overtime rates and pay. A similar lawsuit was initiated in March 2020 in the U.S. District Court for the Eastern District of Kentucky (Brewer v. Alliance Coal, LLC, et al.). Subsequently, four additional lawsuits making similar allegations were initiated against certain of our subsidiaries: filed March 4, 2021 in the Circuit Court for Hopkins County, Kentucky (Johnson v. Hopkins County Coal, LLC, et al.) ; filed April 6, 2021 in the U.S. District Court for the Northern District of West Virginia (Rettig v. Mettiki Coal WV, LLC, et al.); filed April 9, 2021 in the U.S. District Court for the Southern District of Illinois (Cates v. Hamilton County Coal, LLC, et al.) ; and filed April 13, 2021 in the U.S. District Court for the Southern District of Indiana (Prater v. Gibson County Coal, LLC, et al.). The plaintiffs in these cases seek class and collective action certification, which we oppose, and the courts have not yet made 77 Table of Contents definitive final rulings on these issues. The plaintiffs seek to recover alleged compensatory, liquidated and/or exemplary damages for the alleged underpayment, and costs and fees that potentially may be recoverable under applicable law. We believe our ultimate exposure, if any, will not be material to our results of operations or financial position; however, if our current belief as to the merit of the claims in these lawsuits is not upheld, it is reasonably possible that the ultimate resolution of these matters could result in a potential loss that may be material to our results of operations. ​ ITEM 4. MINE SAFETY DISCLOSURES ​ Information concerning mine safety violations or other regulatory matters required by Section 1503(a) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 104 of Regulation S-K (17 CFR 229.104) is included in Exhibit 95.1 to this Annual Report on Form 10-K. ​ 78 Table of Contents PART II ​ ITEM 5. MARKET FOR REGISTRANT ' S COMMON EQUITY, RELATED UNITHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES ​ The common units representing limited partners' interests are listed on the NASDAQ Global Select Market under the symbol "ARLP." The common units began trading on August 20, 1999. There were approximately 53,108 record holders of common units at December 31, 2023. ​ Available cash with respect to each quarter may, at the discretion of our general partner, be distributed to the limited partners as of a record date selected by the general partner. "Available cash," as defined in our partnership agreement, generally means, with respect to any quarter, all cash on hand at the end of each quarter, plus working capital borrowings after the end of the quarter, less cash reserves in the amount necessary or appropriate in the reasonable discretion of our general partner to (a) provide for the proper conduct of our business, (b) comply with applicable law or any debt instrument or other agreement of ours or any of our affiliates, and (c) provide funds for distributions to unitholders for any one or more of the next four quarters. ​ Equity Compensation Plans ​ The information relating to our equity compensation plans required by Item 5 is incorporated by reference to such information as set forth in "Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Unitholder Matters" contained herein. ​ Unit Repurchase Program ​ On May 31, 2018, ARLP announced that the Board of Directors approved the establishment of a unit repurchase program authorizing ARLP to repurchase up to $100 million of its outstanding limited partner common units. In January 2023, the Board of Directors authorized a $93.5 million increase to the unit purchase program, which had $6.5 million of available capacity at the time. The unit repurchase program is intended to enhance ARLP's ability to achieve its goal of creating long-term value for its unitholders and provides another means, along with quarterly cash distributions, of returning cash to unitholders. The program has no time limit and ARLP may repurchase units from time to time in the open market or other privately negotiated transactions. The unit repurchase program authorization does not obligate ARLP to repurchase any dollar amount or number of units, and repurchases may be commenced or suspended from time to time without prior notice. ​ During the three months ended December 31, 2023, we did not repurchase and retire any units. Since the inception of the unit repurchase program, we have repurchased and retired 6,390,446 units at an average unit price of $17.67 for an aggregate purchase price of $112.9 million. The remaining authorized amount for unit repurchases under this program was $80.6 million at December 31, 2023. ​ ​ ​ 79 Table of Contents ITEM 6. [ Reserved] ​ ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS ​ The following discussion of our financial condition and results of operations should be read in conjunction with the historical financial statements and notes thereto included in "Item 8. Financial Statements and Supplementary Data" where you can find more detailed information in "Note 1 – Organization and Presentation" and "Note 2 – Summary of Significant Accounting Policies" regarding the basis of presentation supporting the following financial information. ​ Executive Overview ​ Organization ​ We are a diversified natural resource company that generates operating and royalty income from the production and marketing of coal to major domestic utilities, industrial users and international customers, as well as royalty income from oil & gas mineral interests located in strategic producing regions across the United States. In addition, we continue to position ourselves as a reliable energy provider for the future as we pursue opportunities that support the advancement of energy and related infrastructure. We intend to pursue strategic investments that leverage our core competencies and relationships with electric utilities, industrial customers, and federal and state governments. ​ We are currently the largest coal producer in the eastern United States with seven operating underground mining complexes near many of the major eastern utility generating plants and on major coal hauling railroads in Illinois, Indiana, Kentucky, Maryland, Pennsylvania, and West Virginia, as well as a coal-loading terminal in Indiana. Two of our mines also have loading facilities located on the Ohio River. ​ In addition to our mining operations, Alliance Resource Properties owns or leases substantially all of our coal mineral resources and the majority of our coal mineral reserves in the Illinois and Appalachia Basins that are (a) leased to our internal mining complexes or (b) near our coal mining operations but not yet leased. ​ We currently own minerals interests in approximately 67,700 net royalty acres in premier oil & gas producing regions of the United States, primarily in the Permian (Delaware and Midland), Anadarko (SCOOP/STACK) and Williston (Bakken) basins providing us with diversified exposure to industry-leading operators consistent with our general strategy to grow our oil & gas mineral interest business. ​ We have invested in energy and infrastructure opportunities including our investments in Francis, Infinitum, NGP ET IV, and Ascend which are in the businesses of, respectively, electric vehicle charging stations, electric motor manufacturing, private equity investments in renewable energy, the electrification of our economy or the efficient use of energy, and the manufacturing and recycling of sustainable, engineered battery materials for electric vehicles. ​ Please see "Item 1. Business and Item 2. Properties" in our Annual Report on Form 10-K for the year ended December 31, 2023 for a more detailed discussion of our various businesses. ​ As of December 31, 2023, we had four reportable segments: Illinois Basin Coal Operations, Appalachia Coal Operations, Oil & Gas Royalties and Coal Royalties. We also have an "all other" category referred to as Other, Corporate and Elimination. Our two coal operations reportable segments correspond to major coal producing regions in the eastern United States with similar economic characteristics including coal quality, geology, coal marketing opportunities, mining and transportation methods and regulatory issues. Our Oil & Gas Royalties reportable segment includes our oil & gas mineral interests. Our Coal Royalties reportable segment includes coal mineral reserves and resources owned or leased by Alliance Resource Properties. ​ ● The Illinois Basin Coal Operations reportable segment includes (a) the Gibson mining complex, (b) the Warrior mining complex, (c) the River View mining complex and (d) the Hamilton mining complex. The segment also includes our Mt. Vernon coal-loading terminal in Indiana which operates on the Ohio River, MAC and other support services, and our idled or closed mining complexes. ​ 80 Table of Contents ● The Appalachia Coal Operations reportable segment includes (a) the Mettiki mining complex, (b) the Tunnel Ridge mining complex and (c) the MC Mining mining complex. ​ ● The Oil & Gas Royalties reportable segment includes oil & gas mineral interests held by Alliance Minerals as well as our equity interests in AllDale III. ​ ● The Coal Royalties reportable segment includes substantially all of our coal mineral resources and the majority of our coal mineral reserves owned or leased by Alliance Resource Properties. Approximately 60% of the coal sold by our coal operations' mines was leased from our Coal Royalties entities. ​ ● Other, Corporate and Elimination includes marketing and administrative activities, the Matrix Group , our investments in Francis, Infinitum, NGP ET IV and Ascend, Wildcat Insurance, which assists the ARLP Partnership with its insurance requirements, AROP Funding and Alliance Resource Finance Corporation (both discussed in "Item 8. Financial Statements and Supplementary Data – Note 6 – Long-Term Debt") and other miscellaneous activities. The eliminations included in Other, Corporate and Elimination primarily represent the intercompany coal royalty transactions described above between our Coal Royalties reportable segment and our coal operations' mines. ​ Oil & Gas Acquisitions ​ During 2023, through the JC Resources and Skyland Acquisitions and other ground game acquisitions, we acquired approximately 6,443 oil & gas net royalty acres in the Delaware, Anadarko and Williston basins. These acquisitions enhanced our ownership position in these basins and furthered our business strategy to grow our Oil & Gas Royalties segment through accretive acquisitions. See "Item 8. Financial Statements and Supplementary Data – Note 3 – Acquisitions" for more information. ​ Growth Investments and Opportunities ​ During 2023, we invested $49.6 million in Infinitum and Ascend. This brings our total investment in Francis, Infinitum, NGP ET IV and Ascend to $119.1 million with a remaining commitment of $18.4 million to NGP ET IV. See "Item 8. Financial Statements and Supplementary Data – Note 12 – Equity Investments" for additional information on Francis, Infinitum, NGP ET IV and Ascend. ​ Risks and Uncertainties ​ We face a variety of risks and uncertainties that management considers in the operation and planning of our businesses, which could affect our financial position and results of operations. For additional information regarding our risks and uncertainties that affect our business and the industries in which we operate, see "Item 1A. Risk Factors". ​ Business Strategy ​ Our primary business strategy is to create sustainable, capital-efficient growth in available cash to maximize unitholder returns by: ​ ● expanding our coal operations by adding and developing mines and coal mineral reserves and resources in existing, adjacent or neighboring properties; ● extending the lives of our current mining operations through the acquisition and development of coal mineral reserves and resources using our existing infrastructure; ● continuing to make productivity improvements to remain a low-cost coal producer in each region in which we operate; ● strengthening our position with existing and future customers by offering a broad range of coal qualities, transportation alternatives and customized services; ● developing strategic relationships to take advantage of opportunities within the coal and oil & gas industries and in other industries inside and outside of the Master Limited Partnership sector; ● continuing to make investments in oil & gas mineral interests in various geographic locations within producing basins in the continental United States; 81 Table of Contents ● strengthen and expand our technology company, Matrix Group, as we continue to develop and market industrial, mining and technology products and services worldwide; and ● continuing to identify and make strategic investments in the advancement of energy and related infrastructure opportunities to leverage our core competencies and build platforms for future lines of business with long-term growth and cash flow generation. ​ How We Evaluate Our Performance ​ Our management uses a variety of financial and operational measurements to analyze our performance. Primary measurements include the following: (1) coal sales price per ton; (2) BOE sold; (3) price per BOE; (4) coal royalty tons sold; (5) coal royalty revenue per ton; (6) Segment Adjusted EBITDA Expense per ton; (7) EBITDA; and (8) Segment Adjusted EBITDA. ​ Coal Sales Price per Ton ​ We define coal sales price per ton as total coal sales divided by tons sold. We review coal sales price per ton to evaluate marketing efforts and for market demand and trend analysis. ​ Oil & gas BOE sold ​ We monitor and analyze our BOE sales volumes from the various basins that comprise our portfolio of mineral interests. We also regularly compare projected volumes to actual volumes reported and investigate unexpected variances. ​ Price per BOE ​ We define price per BOE as total oil & gas royalties divided by BOE produced. We review price per BOE to evaluate performance against budget and for trend analysis. ​ Coal Royalty Tons sold ​ We monitor and analyze our coal royalty sales volumes from our various mining subsidiaries for coal leased by Alliance Resource Properties for consistency with our coal operations segments and for trend analysis. ​ Coal Royalty Revenue per Ton ​ We define coal royalty revenue per ton as total coal royalties divided by royalty tons sold. We review coal royalty revenue per ton to evaluate consistency with our coal operations segments and for trend analysis. ​ Segment Adjusted EBITDA Expense per Ton ​ We define Segment Adjusted EBITDA Expense per ton (a non-GAAP financial measure) as the sum of operating expenses, coal purchases and other expense divided by total tons sold. We review Segment Adjusted EBITDA Expense per ton for cost trends. ​ EBITDA ​ We define EBITDA (a non-GAAP financial measure) as net income attributable to ARLP before net interest expense, income taxes and depreciation, depletion and amortization. EBITDA is used as a supplemental financial measure by our management and by external users of our financial statements such as investors, commercial banks, research analysts and others. We believe that the presentation of EBITDA provides useful information to investors regarding our performance and results of operations because EBITDA, when used in conjunction with related GAAP financial measures, (i) provides additional information about our core operating performance and ability to generate and distribute cash flow, (ii) provides investors with the financial analytical framework upon which we base financial, operational, compensation and planning decisions and (iii) presents a measurement that investors, rating agencies and debt holders have indicated is useful in assessing us and our results of operations. ​ 82 Table of Contents Segment Adjusted EBITDA ​ We define Segment Adjusted EBITDA (a non-GAAP financial measure) as net income attributable to ARLP before net interest expense, income taxes, depreciation, depletion and amortization and general and administrative expense. Management therefore is able to focus solely on the evaluation of segment operating profitability as it relates to our revenues and operating expenses, which are primarily controlled by our segments. ​ Analysis of Historical Results of Operations – 2023 Compared with 2022 ​ Consolidated Information ​ Total Revenues ​ Total revenues increased 6.1% to a record $2.57 billion in 2023 compared to $2.42 billion in 2022 primarily due to higher coal sales revenues. ​ Total operating expenses ​ Total operating expenses increased to $1.89 billion in 2023 compared to $1.72 billion in 2022 due primarily to the sale of higher cost purchased coal and increased per ton costs on certain expense items discussed in more detail below. ​ Net income attributable to ARLP ​ Increased revenues and lower income tax expense more than offset higher total operating expenses in 2023, resulting in record net income attributable to ARLP of $630.1 million, or $4.81 per basic and diluted limited partner unit for 2023, compared to $586.2 million, or $4.39 per basic and diluted limited partner unit, for 2022. ​ Coal sales ​ Coal sales increased $108.0 million or 5.1% to $2.21 billion for 2023 from $2.10 billion for 2022. The increase reflects the benefit of higher average coal sales prices, which contributed $175.7 million in additional coal sales, partially offset by lower tons sold, which reduced coal sales by $67.7 million. Higher price realizations in domestic markets drove coal sales prices higher by 8.6% in 2023 to $64.17 per ton sold, compared to $59.07 per ton sold during 2022. ​ Coal - Segment Adjusted EBITDA Expense ​ Beginning in 2023, we redefined Coal - Segment Adjusted EBITDA Expense to reflect the activity of Alliance Coal, which is the holding company for our coal mining operations. We have retrospectively adjusted Coal - Segment Adjusted EBITDA Expense in prior periods to be on the same basis. ​ Segment Adjusted EBITDA Expense for our coal operations increased 8.8% to $1.39 billion, as a result of higher per ton costs. On a per ton basis, Segment Adjusted EBITDA Expense for our coal operations increased 12.4% to $40.38 per ton sold in 2023 compared to $35.91 per ton in 2022, primarily due to certain cost increases, which are discussed below by category: ​ ● Labor and benefit expenses per ton produced, excluding workers' compensation, increased 14.6% to $12.20 per ton in 2023 from $10.65 per ton in 2022. The increase of $1.55 per ton was primarily due to higher incentive benefits and direct labor costs at several mines. ​ ● Material and supplies expenses per ton produced increased 2.6% to $14.02 per ton in 2023 from $13.67 per ton in 2022. The increase of $0.35 per ton produced primarily reflects increases of $0.13 per ton for safety related materials and supplies, $0.11 per ton for various preparation plant expenses and $0.09 per ton for ventilation related expenses , partially offset by a decrease of $0.12 per ton for environmental and reclamation expenses other than longwall subsidence. ​ ● Maintenance expenses per ton produced increased 27.6% to $4.62 per ton in 2023 from $3.62 per ton in 2022. The increase of $1.00 per ton produced was primarily as a result of inflationary cost pressures. 83 Table of Contents ​ ● Production taxes and royalty expenses per ton incurred as a percentage of coal sales prices and volumes increased $0.64 per produced ton sold in 2023 compared to 2022 primarily as a result of higher price realizations and higher federal black lung excise tax as a result of the tax rate increasing effective October 1, 2022, partially offset by a favorable mix of tons sold mined in states without severance taxes. ​ ● Outside coal purchases increased $36.0 million in 2023 as a result of increased sales from purchased coal to meet contractual commitments at our Mettiki longwall operation which experienced challenging geological conditions that delayed development of a new district. Purchased coal generally costs more on a per ton basis than our produced coal. ​ For a definition of Segment Adjusted EBITDA Expense and related reconciliation to its comparable GAAP financial measure, please see below under "—Reconciliation of Non-GAAP Financial Measures." ​ Oil & gas royalties ​ Oil & gas royalty revenues decreased to $137.8 million in 2023 compared to $151.1 million for 2022. The decrease of $13.3 million was primarily due to lower average sales price per BOE, which decreased by 29.4%, partially offset by higher BOE volumes. ​ Other revenues ​ Other revenues principally comprised Matrix Design sales, Mt. Vernon transloading revenues, oil & gas lease bonus revenues, and other miscellaneous sales and revenue activities. Other revenues increased to $76.5 million in 2023 from $52.8 million in 2022. The increase of $23.7 million was primarily due to increased sales of mining technology products by our Matrix Design subsidiary. ​ Income tax expense ​ Income tax expense decreased to $8.3 million for 2023 compared to $54.0 million for 2022 primarily as a result of our recognition of a one-time non-cash income tax charge of $37.3 million during 2022 in connection with the Tax Election. ​ Transportation revenues and expenses ​ Transportation revenues and expenses were $142.3 million and $113.9 million for 2023 and 2022, respectively. The increase of $28.4 million was primarily attributable to increased average third-party transportation rates in 2023 and increased coal shipments for which we arrange third-party transportation. Transportation revenues are recognized when title to the coal passes to the customer and recognized in an amount equal to the corresponding transportation expenses. ​ Segment Adjusted EBITDA ​ Our 2023 Segment Adjusted EBITDA decreased $20.4 million, or 2.0%, to $1.01 billion from 2022 Segment Adjusted EBITDA of $1.03 billion primarily as a result of higher operating expenses and outside coal purchases, partially offset by increased revenues. ​ For a definition of Segment Adjusted EBITDA and related reconciliation to its comparable GAAP financial measure, please see below under "—Reconciliation of Non-GAAP Financial Measures." ​ 84 Table of Contents Segment Information ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ ​ ​ ​ ​ 2023 ​ 2022 (1) ​ Increase (Decrease) ​ (in thousands) ​ Segment Adjusted EBITDA ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Coal Operations ​ $ 514,118 ​ $ 420,684 ​ $ 93,434 ​ 22.2 % Appalachia Coal Operations ​ 330,723 ​ 426,402 ​ (95,679) ​ (22.4) % Oil & Gas Royalties ​ ​ 121,508 ​ ​ 143,179 ​ ​ (21,671) ​ (15.1) % Coal Royalties ​ ​ 41,163 ​ ​ 38,809 ​ ​ 2,354 ​ 6.1 % Other, Corporate and Elimination (2) ​ 4,661 ​ 3,495 ​ 1,166 33.4 % Total Segment Adjusted EBITDA (3) ​ $ 1,012,173 ​ $ 1,032,569 ​ $ (20,396) ​ (2.0) % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal - Tons sold ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Coal Operations ​ 24,724 ​ 24,110 ​ 614 ​ 2.5 % Appalachia Coal Operations ​ 9,718 ​ 11,479 ​ (1,761) ​ (15.3) % Total tons sold ​ 34,442 ​ 35,589 ​ (1,147) ​ (3.2) % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Coal Operations ​ $ 1,364,901 ​ $ 1,219,943 ​ $ 144,958 ​ 11.9 % Appalachia Coal Operations ​ 845,309 ​ 882,286 ​ (36,977) ​ (4.2) % Total coal sales ​ $ 2,210,210 ​ $ 2,102,229 ​ $ 107,981 ​ 5.1 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other revenues ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Coal Operations ​ $ 10,505 ​ $ 6,822 ​ $ 3,683 ​ 54.0 % Appalachia Coal Operations ​ 1,885 ​ 1,481 ​ 404 ​ 27.3 % Oil & Gas Royalties ​ ​ 3,774 ​ ​ 3,837 ​ ​ (63) ​ (1.6) % Coal Royalties ​ ​ 42 ​ ​ 56 ​ ​ (14) ​ (25.0) % Other, Corporate and Elimination ​ 60,244 ​ 40,622 ​ 19,622 ​ 48.3 % Total other revenues ​ $ 76,450 ​ $ 52,818 ​ $ 23,632 ​ 44.7 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Coal Operations ​ $ 861,288 ​ $ 806,080 ​ $ 55,208 ​ 6.8 % Appalachia Coal Operations ​ 516,471 ​ 464,029 ​ 52,442 ​ 11.3 % Oil & Gas Royalties ​ ​ 16,532 ​ ​ 15,395 ​ ​ 1,137 ​ 7.4 % Coal Royalties ​ ​ 24,451 ​ ​ 21,871 ​ ​ 2,580 ​ 11.8 % Other, Corporate and Elimination (2) ​ (14,024) ​ (23,497) ​ 9,473 40.3 % Total Segment Adjusted EBITDA Expense (3) ​ $ 1,404,718 ​ $ 1,283,878 ​ $ 120,840 ​ 9.4 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Oil & Gas Royalties ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Volume - BOE (4) ​ ​ 3,105 ​ ​ 2,405 ​ ​ 700 ​ 29.1 % Oil & gas royalties ​ $ 137,751 ​ $ 151,060 ​ $ (13,309) (8.8) % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal Royalties ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Volume - Tons sold (5) ​ $ 20,186 ​ ​ 21,780 ​ $ (1,594) ​ (7.3) % Intercompany coal royalties ​ 65,572 ​ $ 60,624 ​ 4,948 ​ 8.2 % (1) Recast for the JC Resources Acquisition. For more information, please read "Item 8. Financial Statements and Supplementary Data— Note 1 – Organization and Presentation." (2) Other, Corporate and Elimination includes the elimination of intercompany coal royalty revenues and expenses between our Coal Royalties Segment and our coal operations segments in addition to the expenses for the other miscellaneous activities included in this category. (3) For definitions of Segment Adjusted EBITDA and Segment Adjusted EBITDA Expense and related reconciliations to their respective comparable GAAP financial measures, please see below under "— Reconciliation of Non-GAAP Financial Measures." (4) BOE for natural gas is calculated on a 6:1 basis (6,000 cubic feet of natural gas to one barrel). 85 Table of Contents (5) Represents tons sold by our coal operations segments associated with coal reserves leased from our Coal Royalties Segment. ​ Illinois Basin Coal Operations – Segment Adjusted EBITDA increased 22.2% to $514.1 million in 2023 from $420.7 million in 2022. The increase of $93.4 million was primarily attributable to higher coal sales, which increased 11.9% to $1.36 billion in 2023 from $1.22 billion in 2022, partially offset by increased operating expenses. The increase in coal sales reflects higher coal sales price per ton, which increased by 9.1% compared to 2022 reflecting increased domestic prices, and increased tons sold, which rose 2.5% in 2023 as a result of increased sales volumes at the Warrior, Hamilton and Gibson South mines. Segment Adjusted EBITDA Expense increased 6.8% to $861.3 million in 2023 from $806.1 million in 2022 primarily as a result of increased sales volumes and higher operating expenses per ton. Segment Adjusted EBITDA Expense per ton increased 4.2% or $1.41 per ton sold to $34.84 from $33.43 per ton sold in 2022 primarily as a result of inflationary pressures on numerous expense items, including labor-related expenses and maintenance costs, and increased sales-related expenses due to higher price realizations, partially offset by lower expenses at our Hamilton mine, that experienced an unexpected outage during 2022. ​ Appalachia Coal Operations – Segment Adjusted EBITDA decreased 22.4% to $330.7 million for 2023 from $426.2 million in 2022. The decrease of $95.5 million was primarily attributable to increased operating expenses and lower coal sales volumes. Coal sales volumes decreased 15.3% compared to 2022 as a result of lower production across the region due to lock outages, customer plant maintenance, reduced operating units at MC Mining, challenging geologic conditions that delayed development of a new district at our Mettiki longwall operation and increased longwall move days at our Tunnel Ridge mine. Coal sales prices increased by 13.2% compared to 2022 primarily due to increased domestic price realizations in the region. Segment Adjusted EBITDA Expense increased 11.3% to $516.5 million in 2023 from $464.0 million in 2022 due to higher per ton operating expenses, partially offset by lower volumes. Segment Adjusted EBITDA Expense per ton increased 31.5% to $53.15 compared to $40.42 per ton sold in 2022, as a result of lower volumes previously discussed, purchased coal and inflationary pressures on certain expense items, most notably labor-related expenses and materials and maintenance costs, and increased sales-related expenses due to higher price realizations. ​ Oil & Gas Royalties – Segment Adjusted EBITDA decreased to $121.5 million for 2023 from $143.2 million in 2022. The decrease of $21.7 million was primarily due to lower average sales price per BOE, which decreased 29.4% to $44.37 per BOE, partially offset by increased volumes in 2023, which increased by 29.1%. Higher BOE volumes during 2023 resulted from increased drilling and completion activities on our properties and additional volumes from oil & gas mineral interest acquisitions. ​ Coal Royalties – Segment Adjusted EBITDA increased 6.1% to $41.2 million for 2023 from $38.8 million in 2022. The $2.4 million increase was a result of higher average royalty rates per ton, partially offset by reduced royalty tons sold. ​ Analysis of Historical Results of Operations – 2022 Compared with 2021 ​ Consolidated Information ​ Total Revenues ​ Total revenues increased 53.2% to a record $2.42 billion in 2022 compared to $1.58 billion in 2021 primarily due to substantial increases in prices and volumes from coal operations and royalties and oil & gas royalties. ​ Total operating expenses ​ Total operating expenses increased to $1.75 billion in 2022 compared to $1.36 billion in 2021 due primarily to increased coal sales volumes and ongoing inflationary cost pressures. ​ Net income attributable to ARLP ​ Higher revenues, partially offset by increased total operating expenses and income tax expense, led to significantly higher net income attributable to ARLP, which rose 220.7% to a record $586.2 million for 2022, or $4.39 per basic and diluted limited partner unit, compared to $182.8 million, or $1.36 per basic and diluted limited partner unit, for 2021. ​ 86 Table of Contents Coal sales ​ Coal sales increased $715.3 million or 51.6% to $2.10 billion for 2022 from $1.39 billion for 2021. The increase was attributable to a price variance of $572.6 million due to higher average coal sales prices and a volume variance of $142.7 million resulting from increased tons sold. Coal sales price realizations increased by 37.4% in 2022 to $59.07 per ton sold, compared to $42.98 per ton sold during 2021, due to favorable market conditions. Improved coal demand in both the domestic and export markets during 2022 drove coal sales volumes higher by 10.3% to 35.6 million tons sold compared to 32.3 million tons sold in 2021. ​ Coal - Segment Adjusted EBITDA Expense ​ Segment Adjusted EBITDA Expense for our coal operations increased 33.2% to $1.28 billion, as a result of higher coal sales volumes and inflationary cost pressures. On a per ton basis, Segment Adjusted EBITDA Expense for our coal operations increased 20.8% to $35.91 per ton sold in 2022 compared to $29.73 per ton in 2021, primarily due to certain cost increases, which are discussed below by category: ​ ● Labor and benefit expenses per ton produced, excluding workers' compensation, increased 14.6% to $10.65 per ton in 2022 from $9.29 per ton in 2021. The increase of $1.36 per ton was primarily due to higher labor costs at several mines. ​ ● Material and supplies expenses per