What changed in this filing

/stocks — the workspaceLOADING

Item 2. Properties

2026-02-09 compared with 2025-02-25 · 115 added, 125 removed, 239 unchanged (50% of the section changed)

2 unchanged sentences

We lease our corporate headquarters in Cleveland, Ohio.

We also have leased office space in West Chester, Ohio;

Chicago, Illinois;

and Detroit, Michigan.

We also have leased office space in West Chester, Ohio and Detroit, Michigan.

We own office space located in Burns Harbor, Indiana and our Research and Innovation Center located in Middletown, Ohio.

31 | CLF 2024 FORM 10-K

Location Raw Material

(Tons in millions) State /Province Iron Ore Capacity (lt) HBI Capacity (mt) Coke Capacity (nt) Coal Capacity (nt) Scrap Capacity (mt)

Hibbing Taconite MN l 7.0

Minorca MN l 3.0

(Tons in millions) State /Province Iron Ore Capacity (lt) 1

HBI Capacity (mt) Coke Capacity (nt) Coal Capacity (nt) Scrap Capacity (mt)

Northshore MN l 5.2

Tilden MI l 7.5

United Taconite MN l 6.0

United MN l 5.1

Toledo HBI OH l 1.9

Burns Harbor (Coke) IN l 1.8

Hamilton Works (Coke) ON l 0.7

Lake Erie Works (Coke) ON l 0.7

Hamilton (Coke) ON l 0.7

Lake Erie (Coke) ON l 0.7

Monessen PA l 0.3

2 unchanged sentences

FPT Multiple l N/A

1 As of December 31, 2025

2 Shown at 85.3% ownership share.

During 2025, due to market conditions, we made the decision to partially idle our Hibbing mine.

Our Hibbing mine remained partially idled as of December 31, 2025, but has an annual operational capacity of 4.6 million long tons when fully operational.

3 During 2025, due to market conditions, we made the decision to indefinitely idle our Minorca mine.

Our Minorca mine remained idled as of December 31, 2025, but has an annual operational capacity of 2.8 million long tons.

31 | CLF 2025 FORM 10-K

Location Raw Steel Processing and Finishing

(Tons in millions) State / Province BF-BOF EAF Configured Capacity (nt) Hot-Rolled Cold-Rolled Coated Stainless & Electrical Plate Slab & Other

(Tons in millions) State / Province BF-BOF EAF Configured Capacity (nt) 1

Hot-Rolled Cold-Rolled Coated Stainless & Electrical Plate Slab & Other

Burns Harbor IN l 5.1 l l l l

1 unchanged sentence

Butler PA l 0.3 l

Cleveland Works OH l 3.4 l l l l

Cleveland OH l 3.5 l l l l

Coatesville PA l 0.2 l l

Columbus OH l

Conshohocken PA l

Coshocton OH l

Dearborn Works MI l 3.0 l l l

Gary Plate IN l

Hamilton Works ON l l l

Indiana Harbor Works IN l 4.0 l l l l

Lake Erie Works ON l 2.5 l

Mansfield Works OH l 0.5 l

Middletown Works OH l 3.0 l l l l l

Hamilton ON l l l

Indiana Harbor IN l 5.2 l l l l

Lake Erie ON l 2.5 l

Mansfield OH l 0.5 l

Middletown OH l 2.7 l l l l l

New Carlisle IN l l

Piedmont NC l

Riverdale IL l 0.7 l

Rockport Works IN l l l

Steelton PA l 0.3 l

Rockport IN l l l

Zanesville OH l

1 As of December 31, 2025

2 During 2025, due to market conditions, we made the decision to idle our blast furnace, BOF steel shop, and continuous casting facilities at our Dearborn facility.

This portion of our Dearborn facility remained idled as of December 31, 2025, but has annual raw steel capacity of 3.0 million net tons when fully operational.

STEELMAKING AND FINISHING FACILITIES

Our primary steel producing and finishing facilities are located across Illinois, Indiana, Michigan, Ohio, Pennsylvania, and Ontario.

We operate eight blast furnaces and five EAFs.

Our primary steel producing and finishing facilities are located across Indiana, Michigan, Ohio, Pennsylvania and Ontario.

We operate seven blast furnaces and four EAFs, excluding any currently idled or permanently closed facilities.

Finishing is completed on site at our integrated operations or at one of our 9 stand-alone processing and finishing facilities.

In the aggregate, we have annual configured production capacity of approximately 23.0 million net tons of raw steel.

As of December 31, 2025 and 2024, our annual configured production capacity of raw steel was approximately 20.0 million and 23.0 million net tons, respectively.

During the years ended December 31, 2025 and 2024, our steelmaking facilities produced a total of 18.8 million and 17.7 million net tons of raw steel, respectively.

SCRAP PROCESSING FACILITIES

Our scrap business consists of our subsidiary FPT, which has 22 locations in Michigan, Ohio, Tennessee, Florida and Ontario.

Our scrap business consists of our subsidiary FPT, which has 21 locations in Illinois, Michigan, Mississippi, Ohio, Tennessee and Ontario.

These facilities are primarily located in Michigan and Ohio, which are in close proximity to our scrap consuming steel facilities.

During the years ended December 31, 2024 and 2023, FPT processed approximately 3 million net tons of scrap metal, of which approximately 50% of total output was prime grade.

32 | CLF 2024 FORM 10-K

During each of the years ended December 31, 2025 and 2024, FPT processed approximately 3 million net tons of scrap metal, of which approximately 50% of total output was prime grade.

DIRECT REDUCTION PLANT

2 unchanged sentences

This plant produces a specialized high quality iron alternative to scrap and pig iron and has annual capacity of 1.9 million metric tons of HBI.

During the years ended December 31, 2024 and 2023, our direct reduction plant produced a total of 1.6 million and 1.7 million metric tons of HBI, respectively.

During each of the years ended December 31, 2025 and 2024, our direct reduction plant produced a total of 1.6 million metric tons of HBI.

IRON ORE MINES AND PELLET PLANTS

7 unchanged sentences

Likewise, investors are cautioned not to assume that all or any part of measured or indicated mineral resources will ever be converted to mineral reserves.

32 | CLF 2025 FORM 10-K

See Part I – Item 1A.

1 unchanged sentence

Sustainability and Development Risks – We rely on estimates of our recoverable mineral reserves, which are complex due to geological characteristics of the properties and the number of assumptions made .

The information that follows relating to the Hibbing, Minorca, Northshore, Tilden and United Taconite iron ore mines is derived, for the most part, from, and in some instances is an extract from, the Technical Report Summaries relating to such properties prepared in compliance with Item 601(b)(96) and subpart 1300 of Regulation S-K.

As of December 31, 2025, our individually material mining properties, as determined in accordance with subpart 1300 of Regulation S-K, are the following iron ore mining properties:

Northshore, Tilden and United.

The following summarizes certain information regarding our iron ore mining properties.

The information relating to the Northshore, Tilden and United properties is derived, for the most part, from the technical report summaries relating to such properties prepared in compliance with Item 601(b)(96) and subpart 1300 of Regulation S-K.

Portions of the following information are based on assumptions, qualifications and procedures that are not fully described herein.

5 unchanged sentences

Computerized block models for iron ore are constructed that include all relevant geologic and metallurgical data.

These are used to generate grade and tonnage estimates, followed by detailed mine design and LoM operating schedules.

We currently own or co-own and operate five production-stage iron ore mines in Michigan and Minnesota, as well as one indefinitely idled mine in Michigan.

We have an aggregate annual production capacity of approximately 29 million long tons of iron ore pellets, including our 85.3% share of the Hibbing mine production.

These are used to generate grade and tonnage estimates, followed by detailed mine design and LoM plan operating schedules.

We currently own or co-own and operate five production-stage iron ore mines in Michigan and Minnesota.

While our Tilden, Northshore and United mines were fully operational, as of December 31, 2025 our Minorca mine and a portion of our Hibbing mine were indefinitely idled.

As of December 31, 2025, we had an aggregate annual production capacity of approximately 20.1 million long tons of iron ore pellets, including our 85.3% share of the Hibbing mine production.

Our iron ore mines produce from deposits located within the Biwabik and Negaunee Iron Formation, which are classified as Lake Superior type iron formations that formed under similar sedimentary conditions in shallow marine basins approximately two billion years ago.

5 unchanged sentences

(In millions of long tons) 2025 2024 2023

Minorca 3 3 3

United Taconite 5 5 5

Northshore 3 4 3

Total 17 24 25

1 Hibbing is reported at 85.3% based on our ownership level.

2 In the second quarter of 2022, we temporarily idled our Northshore operations.

The Northshore mine restarted production in the second quarter of 2023.

33 | CLF 2024 FORM 10-K

The following provides an overview of our iron ore properties:

2 In the first half of 2025, we indefinitely idled the Minorca mine and partially idled the Hibbing mine in order to consume excess pellet inventory produced in 2024.

Both remained idled as of December 31, 2025.

All the infrastructure necessary to mine and process significant commercial quantities of iron ore is currently in place at all of our mine locations.

5 unchanged sentences

We maintain the requisite state and federal permits and are in material compliance with all material permits.

Hibbing (85.3% owned) is located immediately north of the city of Hibbing, Minnesota in the center of Minnesota’s Mesabi Iron Range.

The mining and processing operation is located between latitude 47°25’48” N and 47°31’48” N and longitude 93°04’54” W and 92°54’36” W.

Mining began in 1976 as a joint venture between Bethlehem Steel Corporation and Steel Company of Canada.

Cliffs first became involved in the joint venture when it purchased Pickands Mather's 15% share in 1986.

Prior to the AM USA Transaction, we owned 23% of Hibbing, ArcelorMittal USA LLC had a 62.3% interest and U.

Steel had a 14.7% interest.

On December 9, 2020, as a result of the AM USA Transaction, we acquired an additional 62.3% ownership stake in the Hibbing mine and became the majority owner and mine manager.

Hibbing holds 30,705 acres of surface rights, of which 1,150 acres are associated with mineral leases.

The majority of the mineral rights are leased.

The property is comprised of 7,417 acres of mineral leases expiring between 2025 and 2056.

Leases are maintained by making minimum prepaid royalty payments.

Mining leases routinely are renegotiated and renewed as they approach their respective expiration dates.

The operation includes an open pit truck and shovel mine, a concentrator that utilizes single stage crushing, AG mills and magnetic separation to produce a magnetite concentrate, which is then delivered to an on-site pellet plant.

From the site, pellets are transported by BNSF (Burlington Northern Santa Fe, LLC) rail to a ship loading port at Superior, Wisconsin, operated by BNSF.

The net book value of our ownership of Hibbing's property, plant and equipment was $44 million as of December 31, 2024.

For further information, see Exhibit 96.1, the Technical Report Summary on the Hibbing Taconite Property, Minnesota, USA, prepared for the Company by the QP, SLR, with an effective date of December 31, 2021.

Minorca (100% owned) is located in the center of Minnesota’s Mesabi Iron Range.

The Laurentian Pit is located near the City of Gilbert, Minnesota at latitude 47°30'0"N and longitude 92°26’30"W, East 1 Pit is located at latitude 47°31'30"N and longitude 92°23’30"W, and East 2 Pit is located just west of the City of Biwabik at latitude 47°32'0"N and longitude 92°22’30"W.

The Minorca plant is located approximately seven miles to the northwest, near the town of Virginia, Minnesota at latitude 47°33'30"N and longitude 92°31.5'30"W.

Operations commenced in 1976 as an asset of Inland Steel Company.

In 1998, Ispat International purchased Inland Steel and, in 2004, merged with LNM Holdings and International Steel Group to form Mittal Steel, which in 2007 merged with Arcelor to form ArcelorMittal S.A.

Minorca has been wholly owned by Cliffs since the 2020 AM USA Transaction.

34 | CLF 2024 FORM 10-K

Minorca holds 13,690 acres of surface rights, of which 282 acres are associated with mineral leases.

100% of the mineral rights are leased.

The property is comprised of 3,135 acres of mineral leases expiring between 2035 and 2056.

Leases are maintained by making minimum prepaid royalty payments.

Mining leases routinely are renegotiated and renewed as they approach their respective expiration dates.

The operation includes a concentrating and pelletizing facility, along with two open pit iron ore mines located approximately seven miles from the processing facilities.

The processing operations consist of a crushing facility, a three-line concentration facility and a single-line straight grate pelletizing plant.

Pellets are transported by CN rail to ports on Lake Superior.

The net book value of Minorca's property, plant and equipment was $208 million as of December 31, 2024.

For further information, see Exhibit 96.2, Technical Report Summary on the Minorca Property, Minnesota, USA, prepared for the Company by the QP, SLR, with an effective date of December 31, 2021.

The following provides an overview of our individually material iron ore properties:

Northshore's (100% owned) mine is located on the northeastern edge of the Mesabi Iron Range in northeastern Minnesota, approximately four miles southeast of Babbitt, Minnesota at latitude 47°40'12.15"N and longitude 91°53'1.28"W.

The processing facility is approximately 41 miles to the southeast and immediately adjacent to the city of Silver Bay in Lake County, Minnesota at latitude 47°17'38.95"N and longitude 91°15'23.38"W.

33 | CLF 2025 FORM 10-K

Operations commenced in 1952 as an asset of the Reserve Mining Company and continued production until 1986 when Reserve Mining declared bankruptcy.

10 unchanged sentences

The concentrator utilizes rod mills and magnetic separation to produce a magnetite concentrate, which is delivered to the pellet plant located on-site.

The plant can produce both standard and DR-grade pellets.

The plant can produce both standard and direct reduction-grade pellets.

The plant site has its own ship loading port located on Lake Superior.

1 unchanged sentence

For further information, see Exhibit 96.1, Technical Report Summary on the Northshore Property, Minnesota, USA, prepared for the Company by the QP, SLR, with an effective date of December 31, 2021.

35 | CLF 2024 FORM 10-K

Tilden (100% owned) is located in Marquette County in Michigan’s Upper Peninsula, on the Marquette Iron Range, approximately five miles south of the city of Ishpeming, Michigan at latitude 46° 29' N and longitude 87° 40' W.

6 unchanged sentences

Mining leases routinely are renegotiated and renewed as they approach their respective expiration dates.

Operations include an open pit truck and shovel mine, a concentrator that utilizes single stage crushing, AG mills and floatation to produce hematite concentrates that are then supplied to the on-site pellet plant.

Operations include an open pit truck and shovel mine, a concentrator that utilizes single stage crushing, autogenous grinding mills and floatation to produce hematite concentrates that are then supplied to the on-site pellet plant.

From the site, pellets are transported by our LS&I (Lake Superior & Ishpeming Railroad Company) rail to a ship loading port at Marquette, Michigan, operated by LS&I.

1 unchanged sentence

For further information, see Exhibit 96.2, Technical Report Summary on the Tilden Property, Michigan, USA, prepared for the Company by the QP, SLR, with an effective date of December 31, 2021.

UNITED TACONITE

United Taconite's (100% owned) mine and offices are located on Minnesota's Mesabi Iron Range just north of Eveleth, Minnesota at latitude 47°29'1.62" N, longitude 92°32'23.69" W.

34 | CLF 2025 FORM 10-K

United’s (100% owned) mine and offices are located on Minnesota's Mesabi Iron Range just north of Eveleth, Minnesota at latitude 47°29'1.62" N, longitude 92°32'23.69" W.

The processing facilities are located approximately eight miles to the southeast.

The property commenced operations as an asset of Eveleth Taconite Company in 1965 before it was purchased by United Taconite (70% Cliffs and 30% Laiwu Steel) in December 2003.

The property commenced operations as an asset of Eveleth Taconite Company in 1965 before it was purchased by United (70% Cliffs and 30% Laiwu Steel) in December 2003.

The property has been a wholly owned subsidiary of Cliffs since 2008.

United Taconite owns 14,199 acres of surface rights, of which 703 acres are associated with mineral leases.

United owns 14,199 acres of surface rights, of which 703 acres are associated with mineral leases.

An additional 145 acres of surface rights are leased from the State of Minnesota.

6 unchanged sentences

From the plant site, pellets are transported by CN rail to a ship loading port at Duluth, Minnesota, operated by CN.

The net book value of United Taconite's property, plant and equipment was $570 million as of December 31, 2024.

For further information, see Exhibit 96.4, Technical Report Summary on the United Taconite Property, Minnesota, USA, prepared for the Company by the QP, SLR, with an effective date of December 31, 2021.

36 | CLF 2024 FORM 10-K

The net book value of United’s property, plant and equipment was $554 million as of December 31, 2025.

For further information, see Exhibit 96.3, Technical Report Summary on the United Property, Minnesota, USA, prepared for the Company by the QP, SLR, with an effective date of December 31, 2021.

MINERAL RESOURCES

2 unchanged sentences

A detailed breakdown of the mineral resources exclusive of mineral reserves is presented in the table below.

Mineral resources were defined and constrained within open-pit shells, prepared by Cliffs, and based on a US$90.00/WLT pellet price, while meeting defined cut-off grade criteria and existing pellet specifications.

All mineral resource estimates were reviewed and validated by the QP, SLR.

The following represents iron ore mineral resources, exclusive of mineral reserves, as of December 31, 2024 and 2023:

Mineral resources were defined and constrained within open-pit shells, prepared by Cliffs, and based on a US$90.00/WLT pellet price for our Minnesota iron ore mines and on a US$100.00/WLT pellet price for our Michigan iron ore mine, freight-on-board (FOB) Lake Superior, while meeting defined cut-off grade criteria and existing pellet specifications.

All estimates of mineral resource were reviewed and validated by the QP, SLR.

35 | CLF 2025 FORM 10-K

The following represents iron ore mineral resources, exclusive of mineral reserves, as of December 31, 2025:

Iron Ore Mineral Resources

8 unchanged sentences

Tilden — — 104 33.2 104 33.2 35% 99 33.7

United Taconite 92 23.6 639 22.2 731 22.4 32% 26 21.5

United 92 23.6 639 22.2 731 22.4 32% 26 21.5

1 Hibbing is reported at 85.3% based on our ownership level.

2 unchanged sentences

Mineral resources are estimated using the following cut-off grades:

25% FeT for Tilden hematite;

13% magnetic Fe for Hibbing;

16% magnetic Fe for Minorca;

15% magnetic Fe for Northshore;

25% FeT for Tilden hematite;

and 17% magnetic Fe for United.

Tonnage is reported in long tons equivalent to 2,240 pounds and has been rounded to the nearest 100,000.

For comparison purposes, the following represents iron ore mineral resources, exclusive of mineral reserves, as of December 31, 2024:

Iron Ore Mineral Resources

Measured Indicated Measured + Indicated Process Recovery Inferred

(In millions of long tons) Tonnage % Grade Tonnage % Grade Tonnage % Grade Tonnage % Grade

Total Iron Ore 1,351 22.5 1,483 23.6 2,834 23.1 31% 420 32.4

Michigan — — 135 35.5 135 35.5 36% 350 34.7

Minnesota 1,351 22.5 1,348 22.4 2,699 22.4 31% 70 21.0

8 19.2 1 18.7 9 19.2 25% — —

Minorca 484 22.9 317 22.9 801 22.9 33% 30 21.1

Northshore 767 22.1 391 22.4 1,158 22.2 26% 14 19.8

Tilden — — 135 35.5 135 35.5 36% 350 34.7

United 92 23.6 639 22.2 731 22.4 32% 26 21.5

1 Hibbing is reported at 85.3% based on our ownership level.

Reference point selected is the saleable tons based on the process recovery.

Process recovery may change based on the required saleable product mix and is reported as wet product percentage.

Mineral resources are estimated using the following cut-off grades:

13% magnetic Fe for Hibbing;

16% magnetic Fe for Minorca;

17% magnetic Fe for United Taconite;

and 13% magnetic Fe for Hibbing.

15% magnetic Fe for Northshore;

25% FeT for Tilden hematite;

and 17% magnetic Fe for United.

Tonnage is reported in long tons equivalent to 2,240 pounds and has been rounded to the nearest 100,000.

Mineral resources are reported at a $90.00/lt wet standard pellet price freight-on-board (FOB) Lake Superior, which is based on the mine planning model's three-year trailing average of the realized product revenue rate.

We did not have any material changes to our mineral resources during 2024.

The material assumptions and criteria used for the mineral resource estimates, including but not limited to leases, permits and geotechnical pit design, are covered in more detail in Sections 11 through 13 of the respective Technical Report Summaries filed as Exhibits 96.1 through 96.5 to this Annual Report on Form 10-K.

Mineral resources decreased by 8.7% during 2025 primarily due to a reduction in inferred resources resulting from the Tilden LoM plan reserve analysis performed during 2025.

The material assumptions and criteria used for the mineral resource estimates for Northshore, Tilden and United, including but not limited to leases, permits and geotechnical pit design, are covered in more detail in Sections 11 through 13 of the respective Technical Report Summaries filed as Exhibits 96.1 through 96.3 to this Annual Report on Form 10-K.

36 | CLF 2025 FORM 10-K

MINERAL RESERVES

5 unchanged sentences

Mineral reserves are based on pricing that does not exceed the three-year trailing average index price of iron pellets adjusted to realized price.

We evaluate and analyze, and engage QPs to review and verify, mineral reserves in accordance with our mineral policy and SEC requirements and then complete updated LoM plans.

The table below identifies the year in which the latest updated LoM plan was completed.

We evaluate and analyze, and engage QPs to review and verify, mineral reserves in accordance with our mineral policy and SEC requirements and then complete LoM plan reserve analyses.

The table below identifies the year in which the latest LoM plan reserve analysis was completed.

Mineral reserves estimates for our iron mines are constrained by fully designed open pits developed using three-dimensional modeling techniques.

1 unchanged sentence

All operations' mineral reserves have been adjusted net of production through year-end 2025.

All mineral reserves estimates as of December 31, 2021 were reviewed and validated by the QP, SLR.

37 | CLF 2024 FORM 10-K

All mineral reserves estimates were reviewed and validated by the QP, SLR.

The following represents iron ore mineral reserves as of December 31, 2025.

These estimates are periodically updated to reflect past iron ore production, updated mine plans, new exploration information, and other geologic or mining data.

Mineral reserves were defined and constrained within open-pit shells, prepared by Cliffs, and based on a US$90.00/WLT pellet price for our Minnesota iron ore mines and on a US$100.00/WLT pellet price for our Michigan iron ore mine, freight-on-board (FOB) Lake Superior, while meeting defined cut-off grade criteria and existing pellet specifications.

All estimates of mineral reserves were reviewed and validated by the QP, SLR.

Iron Ore Mineral Reserves

9 unchanged sentences

Tilden 2025 2 36.1 436 34.7 438 34.7 35%

United Taconite 2019 98 23.4 631 22.1 729 22.3 33%

United 2019 85 23.5 631 22.1 716 22.3 33%

1 Hibbing is reported at 85.3% based on our ownership level.

2 Incremental adjustments to Hibbing’s mineral reserves are due to acquisition of new leases and mining permits both within and directly adjacent to Hibbing's current operating footprint, as well as reconciliation of the previous four years of depletion with increased levels of dilution.

Reference point selected by the QP is the saleable tons based on the process recovery.

1 unchanged sentence

Mineral reserves are estimated using the following cut-off grades:

25% FeT for Tilden hematite;

19% magnetic Fe for Northshore;

13% magnetic Fe for Hibbing;

16% magnetic Fe for Minorca;

17% magnetic Fe for United Taconite;

and 13% magnetic Fe for Hibbing.

19% magnetic Fe for Northshore;

25% FeT for Tilden hematite;

and 17% magnetic Fe for United.

Tonnage is reported in long tons equivalent to 2,240 pounds and has been rounded to the nearest 100,000.

Mineral reserves are classified as probable if not scheduled within the first 20 years.

Mineral reserves are reported at a $90.00/lt wet standard pellet price freight-on-board (FOB) Lake Superior, which is based on the mine planning model's three-year trailing average of the realized product revenue rate.

The material assumptions and criteria used for the mineral reserves estimates, including but not limited to leases, permits and geotechnical pit design, are covered in more detail in Sections 11 through 13 of the respective Technical Report Summaries filed as Exhibits 96.1 through 96.5 to this Annual Report on Form 10-K.

The material assumptions and criteria used for the mineral reserves estimates for Northshore, Tilden and United, including but not limited to leases, permits and geotechnical pit design, are covered in more detail in Sections 11 through 13 of the respective Technical Report Summaries filed as Exhibits 96.1 through 96.3 to this Annual Report on Form 10-K.

37 | CLF 2025 FORM 10-K

11 unchanged sentences

Tilden 4 35.3 458 34.6 462 34.6 37%

United Taconite 114 23.1 631 22.1 745 22.3 33%

United 98 23.4 631 22.1 729 22.3 33%

1 Hibbing is reported at 85.3% based on our ownership level.

2 unchanged sentences

Mineral reserves are estimated using the following cut-off grades:

25% FeT for Tilden hematite;

13% magnetic Fe for Hibbing, 16% magnetic Fe for Minorca;

19% magnetic Fe for Northshore;

16% magnetic Fe for Minorca;

17% magnetic Fe for United Taconite;

and 13% magnetic Fe for Hibbing.

25% FeT for Tilden hematite;

and 17% magnetic Fe for United.

Tonnage is reported in long tons equivalent to 2,240 pounds and has been rounded to the nearest 100,000.

Mineral Reserves are classified as probable if not scheduled within the first 20 years.

Mineral Reserves are reported at a $90.00/lt wet standard pellet price freight-on-board (FOB) Lake Superior, which is based on the mine planning model's three-year trailing average of the realized product revenue rate.

Overall, mineral reserves estimates as of December 31, 2024, as compared to the prior-year period, decreased by 1%, which was driven by mining depletion offset by the Hibbing mine plan update.

Overall, mineral reserves estimates as of December 31, 2025, as compared to the prior-year period, decreased by 2%, which was driven by mining depletion.

INTERNAL CONTROLS DISCLOSURE

We demonstrated repeated attainment of annual production and quality targets for at least 45 years at each material iron ore mine operated by the Company.

Each material iron ore mine operated by the Company has demonstrated repeated attainment of annual production and quality targets for over 50 years.

Internal controls the Company uses in its industry-standard approach to exploration and mineral resource and reserve estimation efforts are governed by its Mineral Reserve and Mineral Resource Estimation Policy and are detailed in Cliffs’ minimum operating standards for Resource Estimation and Strategic Mine Planning.

16 unchanged sentences

The QP, SLR, reviewed Cliffs' QA/QC practices and provided recommendations for further work.

Where QA/QC programs were still in development at that time and prior to resource estimation, Cliffs conducted data verification studies utilizing a suite of blind crude ore standards and blind duplicates from historical sample

39 | CLF 2024 FORM 10-K

reserves within the LoM plan.

Where unaccredited labs provided data used in resource estimation, check lab studies were initiated to verify analytical results.

Cliffs is currently working toward completing alignment of QA/QC protocols at each mine to the Company’s current best practice by formalizing procedures.

Cliffs continues to work toward completing alignment of QA/QC protocols at each mine to the Company’s current best practice by formalizing procedures.

38 | CLF 2025 FORM 10-K

Cliffs maintains exploration drill hole data in an externally-managed, access-controlled acQuire database that is backed up online at regularly scheduled intervals to provide data redundancy and security.

33 unchanged sentences

Our Monessen and Warren facilities produce furnace coke and related by-products in Monessen, Pennsylvania and Warren, Ohio, respectively.

We also operate cokemaking facilities located within our Burns Harbor, Lake Erie Works and Hamilton Works locations.

We also operate cokemaking facilities located within our Burns Harbor, Lake Erie and Hamilton locations.

These facilities have an aggregate annual rated capacity of 4.0 million net tons.

During each of the years ended December 31, 2024 and 2023, our cokemaking facilities produced 2.4 million net tons of coke.

During the years ended December 31, 2025 and 2024, our cokemaking facilities produced 3.1 million and 2.4 million net tons of coke, respectively.

OTHER BUSINESSES

Our Tubular operating segment consists of our subsidiary Tubular Components, which has plants in Walbridge, Ohio and Columbus, Indiana.

Our Tubular operating segment consists of plants in Walbridge, Ohio and Columbus, Indiana.

The Walbridge plant operates six electric resistance welded tube mills and one laser re-cutting line on owned property.

The Columbus plant operates five electric resistance welded tube mills and four high-speed cold saws on leased property.

Our Tooling and Stamping operating segment consists of our subsidiary Tooling and Stamping and its related companies, which provides advanced-engineered solutions, tool design and build, hot- and cold-stamped steel components and complex assemblies for the automotive market across 10 plants, of which certain of these are under long-term lease agreements, in Ontario, Alabama, Kentucky and Tennessee.

Its facilities feature eight large-bed, hot-stamping presses, providing 14 lines of production;

The Columbus plant operates five electric resistance welded tube mills, four high-speed cold saws, and one laser re-cutting line on leased property.

Our Tooling and Stamping operating segment provides advanced-engineered solutions, tool design and build, hot- and cold-stamped steel components and complex assemblies for the automotive market across 10 plants, of which certain of these are under long-term lease agreements, in Ontario, Alabama, Kentucky and Tennessee.

Its facilities feature seven large-bed, hot-stamping presses, providing 13 lines of production;

60 cold-stamping presses ranging from 150 net tons to 3,000 net tons of pressing capacity;

18 large-bed, high-tonnage tryout presses with

40 | CLF 2024 FORM 10-K

prove-out capabilities for new tool builds;

18 large-bed, high-tonnage tryout presses with prove-out capabilities for new tool builds;

and 173 multi-axis welding assembly cells.

2 unchanged sentences

the Netherlands, Italy, Germany, France, Spain and the United Kingdom.

39 | CLF 2025 FORM 10-K

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 2. Properties