Orion Group Holdings Inc 10-Q

ITEM 5. OTHER INFORMATION None. ITEM 6. EXHIBITS Exhibit Number Description 3.1 ​ Amended and Restated Certificate of Incorporation of Orion Group Holdings, Inc. (incorporated herein by reference to Exhibit 3.1 to the Company’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2016, filed with the Securities and Exchange Commission on August 5, 2016 (File No. 001-33891)). 3.2 ​ Amended and Restated Bylaws of Orion Group Holdings, Inc. (incorporated herein by reference to Exhibit 3.2 to the Company’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2016, filed with the Securities and Exchange Commission on August 5, 2016 (File No. 001-33891)). * 31 .1 ​ Certification of the Chief Executive Officer Pursuant to Rules 13a-14(a)/15d-14(a) of the Securities Exchange Act of 1934, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. * 31 .2 ​ Certification of the Chief Financial Officer Pursuant to Rules 13a-14(a)/15d-14(a) of the Securities Exchange Act of 1934, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. † 32 .1 ​ Certification of the Chief Executive Officer and the Chief Financial Officer pursuant to Title 18 U.S.C. 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. *101.INS ​ XBRL Instance Document. *101.SCH ​ Inline XBRL Taxonomy Extension Schema Document. *101.CAL ​ Inline XBRL Extension Calculation Linkbase Document. *101.DEF ​ Inline XBRL Taxonomy Extension Definition Linkbase Document. *101.LAB ​ Inline XBRL Taxonomy Extension Label Linkbase Document. *101.PRE ​ Inline XBRL Taxonomy Extension Presentation Linkbase Document. *104 ​ Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101) * Filed herewith † Furnished herewith ​ 45 ​ Table of Contents ​ ​ SIGNATURES Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized. ​ ​ ​ ​ ​ ​ ORION GROUP HOLDINGS, INC. ​ ​ ​ April 30, 2021 By: /s/ Mark R. Stauffer ​ ​ Mark R. Stauffer President and Chief Executive Officer ​ ​ ​ April 30, 2021 By: /s/ Robert L. Tabb ​ ​ Robert L. Tabb Executive Vice President and Chief Financial Officer ​ ​ ​ ​ ​ ​ ​ 46 ​