Exhibit 3.1

AMENDED AND RESTATED CERTIFICATE OF INCORPORATION

OF

CRIMSON EXPLORATION INC.

FIRST: The name of the Corporation is:

CRIMSON EXPLORATION INC.

SECOND: The address of the Corporation’s registered office in the State of Delaware is 2711 Centerville Road, Suite 400, in the City of Wilmington, County of New Castle, 19808 and its registered agent at such address is Corporation Service Company.

THIRD: The purpose of the Corporation is to engage in any lawful act or activity for which corporations may be organized under the General Corporation Law of Delaware.

FOURTH: The total number of shares of stock which the Corporation shall have authority to issue is Three Thousand (3,000) shares of Common Stock with no par value per share.

FIFTH: The mailing address of the Corporation is 717 Texas Avenue, Suite 2900, Houston, Texas 77002.

SIXTH: Elections of directors need not be by ballot unless the Bylaws of the Corporation shall so provide.

SEVENTH: The Board of Directors of the Corporation may make Bylaws and from time to time may alter, amend or repeal Bylaws.

EIGHTH: No person who is or was a director of the Corporation shall be personally liable to the Corporation or any of its stockholders for monetary damages for breach of fiduciary duty as a director, except to the extent such exemption from liability or limitation thereof is not permitted by the General Corporation Law of the State of Delaware (“DGCL”) as the same exists or hereafter may be amended. If the DGCL is hereafter amended to authorize corporate action further limiting or eliminating the liability of directors, then the liability of a director to the Corporation or its stockholders shall be limited or eliminated to the fullest extent permitted by the DGCL, as so amended. Any repeal or amendment of this Section Eighth by the stockholders of the Corporation or by changes in law, or the adoption of any other provision of this Certificate inconsistent with this Section Eighth will, unless otherwise required by law, be prospective only (except to the extent such amendment or change in law permits the Corporation to further limit or eliminate the liability of directors) and shall not adversely affect any right or protection of a director of the Corporation existing at the time of such repeal or amendment or adoption of such inconsistent provision with respect to acts or omissions occurring prior to such repeal or amendment or adoption of such inconsistent provision.

NINTH: (a) Each person who is or was made a party or is threatened to be made a party to or is otherwise involved in any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (hereinafter a “proceeding”) by reason of the fact that he or she is or was a director of the Corporation or, while a director of the Corporation, is or was serving at the request of the Corporation as a director, officer, employee or agent of another corporation or of a partnership, joint venture, trust or other enterprise, including service with respect to an employee benefit plan (hereinafter a “Covered Person”), whether the basis of such proceeding is alleged action in an official capacity as a director, officer, employee or agent, or in any other capacity while serving as a director, officer, employee or agent, shall be indemnified and held harmless by the Corporation to the fullest extent authorized or permitted by applicable law, as the same exists or may hereafter be amended, against all expense, liability and loss (including, without limitation, attorneys’ fees, judgments, fines, ERISA excise taxes and penalties and amounts paid in settlement) reasonably incurred or suffered by such Covered Person in connection with such proceeding, and such right to indemnification shall continue as to a person who has ceased to be a director, officer, employee or agent and shall inure to the benefit of his or her heirs, executors and administrators; provided, however, that, except for proceedings to enforce rights to indemnification, the Corporation shall indemnify a Covered Person in connection with a proceeding (or part thereof) initiated by such Covered Person only if such proceeding (or part thereof) was authorized by the Board. The right to indemnification conferred by this Section shall be a contract right and shall include the right to be paid by the Corporation the expenses incurred in defending or otherwise participating in any such proceeding in advance of its final disposition.

(b) The rights conferred on any Covered Person by this Section Ninth shall not be exclusive of any other rights which any Covered Person may have or hereafter acquire under law, this Certificate, the Bylaws, an agreement, vote of stockholders or disinterested directors, or otherwise.

(c) Any repeal or amendment of this Section Ninth by the stockholders of the Corporation or by changes in law, or the adoption of any other provision of this Certificate inconsistent with this Section Ninth, will, unless otherwise required by law, be prospective only (except to the extent such amendment or change in law permits the Corporation to provide broader indemnification rights on a retroactive basis than permitted prior thereto), and will not in any way diminish or adversely affect any right or protection existing at the time of such repeal or amendment or adoption of such inconsistent provision in respect of any act or omission occurring prior to such repeal or amendment or adoption of such inconsistent provision.

(d) This Section Ninth shall not limit the right of the Corporation, to the extent and in the manner authorized or permitted by law, to indemnify and to advance expenses to persons other than Covered Persons.

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TENTH: Any action that is permitted to be taken by the stockholders of the Corporation at any annual or special meeting of stockholders may be effected by written consent of the stockholders in lieu of a meeting of stockholders.

ELEVENTH: Whenever a compromise or arrangement is proposed between this Corporation and its creditors or any class of them and/or between this Corporation and its stockholders or any class of them, any court of equitable jurisdiction within the State of Delaware may, on the application in a summary way of this Corporation or of any creditor or stockholder thereof or on the application of any receiver or receivers appointed for this Corporation under the provisions of section 291 of Title 8 of the Delaware Code or on the application of trustees in dissolution or of any receiver or receivers appointed for this Corporation under the provisions of section 279 of Title 8 of the Delaware Code order a meeting of the creditors or class of creditors, and/or of the stockholders or class of stockholders of this Corporation, as the case may be, to be summoned in such manner as the said court directs. If a majority in number representing three-fourths in value of the creditors or class of creditors, and/or of the stockholders or class of stockholders of this Corporation, as the case may be, agree to any compromise or arrangement and to any reorganization of this Corporation as consequence of such compromise or arrangement, the said compromise or arrangement and the said reorganization shall, if sanctioned by the court to which the said application has been made, be binding on all the creditors or class of creditors, and/or on all the stockholders or class of stockholders, of this Corporation, as the case may be, and also on this Corporation.

IN WITNESS WHEREOF, Crimson Exploration Inc. has caused this Amended and Restated Certificate of Incorporation to be signed by its President and Chief Executive Officer on this 1st day of October, 2013.

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