As filed with the Securities and Exchange Commission on July 6, 2015

Registration No. 333-203259

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

Post-Effective Amendment No. 1 to

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Genesis Energy, L.P.

Genesis Energy Finance Corporation

(and the subsidiaries identified below in the Table of Subsidiary Guarantor Registrants)

(Exact name of registrant as specified in its charter)

919 Milam, Suite 2100

Houston, Texas 77002

(713) 860-2500

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Kristen O. Jesulaitis

919 Milam, Suite 2100

Houston, Texas 77002

Telephone: (713) 860-2500

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copy to:

J. Vincent Kendrick

Akin Gump Strauss Hauer & Feld LLP

1111 Louisiana Street, 44 ^th Floor

Houston, Texas 77002

Telephone: (713) 220-5839

Approximate Date of Commencement of Proposed Sale to the Public: From time to time after the registration statement becomes effective.

If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.   ¨

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.   x

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.   ¨

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.   ¨

If this form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.   x

If this form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.   x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

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EXPLANATORY NOTE

This Post-Effective Amendment to the Registration Statement (File No. 333-203259) is being filed for the purpose of adding Antelope Refining, LLC, a Delaware limited liability company, Powder River Crude Services, LLC, a Delaware limited liability company , Thunder Basin Holdings, LLC, a Delaware limited liability company, and Thunder Basin Pipeline, LLC, a Delaware limited liability company (collectively, the “Additional Co-Registrants”), each a wholly owned subsidiary of Genesis Energy, L.P., as Co-Registrants that may potentially be guarantors of some or all of the debt securities with respect to which offers and sales are registered under this Registration Statement. No changes or additions are being made hereby to the base prospectus that already forms a part of the Registration Statement. Accordingly, such base prospectus is being omitted from this filing.

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PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

The following table sets forth the costs and expenses, other than selling or underwriting discounts and commissions, we expect to incur in connection with the issuance and distribution of the securities being registered. All amounts shown are estimated except the Commission registration fee. Genesis Energy, L.P. will bear all such costs and expenses.

Genesis Energy, L.P.

Section 17-108 of the Delaware Revised Uniform Limited Partnership Act provides that, subject to such standards and restrictions, if any, as are set forth in its limited partnership agreement, a Delaware limited partnership may, and shall have the power to, indemnify and hold harmless any partner or other person from and against all claims and demands whatsoever. The partnership agreement of Genesis Energy, L.P. provides that Genesis Energy, L.P. will indemnify (to the fullest extent permitted by applicable law) certain persons (each, an “Indemnitee”) from and against any and all losses, claims, damages, liabilities, joint or several, expenses (including legal fees and expenses), judgments, fines, penalties, interest, settlements or other amounts incurred by such Indemnitee in connection with any claim, demand, action, suit or proceeding to which the Indemnitee is or was an actual or threatened party by reason or its status as an Indemnitee. This indemnity is available only if the Indemnitee acted in good faith, in a manner in which such Indemnitee believed to be in, or not opposed to, the best interests of Genesis and, with respect to any criminal proceeding, had no reasonable cause to believe its conduct was unlawful. Indemnitees include our general partner, any Departing Partner (as defined in the partnership agreement of Genesis Energy, L.P.), any affiliate of our general partner or any Departing Partner, any person who is or was a director, officer, employee, agent or trustee of our general partner or any Departing Partner or any affiliate of either (including Genesis Energy, L.P. and its subsidiaries), or any person who is or was serving at the request of our general partner, any Departing Partner, or any such affiliate as a director, officer, employee, member, partner, agent fiduciary or trustee of another person. Expenses subject to indemnity will be paid by the partnership to the Indemnitee in advance, subject to receipt of an undertaking by or on behalf of the Indemnitee to repay such amount if it is ultimately determined that the Indemnitee is not entitled to indemnification. Genesis Energy, L.P. will, to the extent commercially reasonable, purchase and maintain insurance on behalf of the Indemnitees, whether or not Genesis Energy, L.P. would have the power to indemnify such Indemnitees against liability under the partnership agreement.

Genesis Energy, L.P. has entered into indemnification agreements with the directors of its general partner. Those agreements provide, among other things, that Genesis Energy, L.P. will indemnify each director in the event that such director becomes a party or otherwise a participant in any action or proceeding on account of such director’s service as a director (or service for another entity in any capacity at the request of our general partner or Genesis Energy, L.P.) to the fullest extent permitted by applicable law. Under each indemnification agreement, Genesis Energy, L.P. has agreed to pay, in advance of the final disposition of any such action or proceeding, expenses (including attorneys’ fees) incurred by each director in defending or otherwise responding to such action or proceeding. The contractual rights to indemnification provided by the indemnification agreements are subject to the limitations and conditions specified in those agreements, and

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are in addition to any other rights the directors may have under our general partner’s limited liability company agreement and the partnership agreement of Genesis Energy, L.P. (each as amended from time to time) and applicable law. Our general partner is party to each of those indemnification agreements. Genesis Energy, L.P. has joint and several liability with our general partner for all obligations owed to those directors under those indemnification agreements. Under the partnership agreement of Genesis Energy, L.P., it has agreed to reimburse and indemnify our general partner for all costs and expenses it incurs in connection with being general partner of Genesis Energy, L.P., including any costs and expenses related to indemnifying its directors.

Reference is made to Exhibit 1.1 hereto, which will contain provisions for indemnification of Genesis Energy, L.P., our general partner and its directors, officers, and any controlling persons, against certain liabilities for information furnished by the underwriters and/or agents, as applicable, expressly for use in a prospectus supplement.

Genesis Energy Finance Corporation

Section 145 of the Delaware General Corporation Law empowers a Delaware corporation to indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding (other than an action by or in the right of the corporation) by reason of the fact that such person is or was a director, officer, employee or agent of another corporation or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by him in connection with such action, suit or proceeding if he acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his conduct was unlawful. Similar indemnity is authorized for such persons against expenses (including attorneys’ fees) actually and reasonably incurred in connection with the defense or settlement of any such threatened, pending or completed action or suit if such person acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation, and provided further that (unless a court of competent jurisdiction otherwise provides) such person shall not have been adjudged liable to the corporation. Any such indemnification may be made only as authorized in each specific case upon a determination by the stockholders or disinterested directors or by independent legal counsel in a written opinion that indemnification is proper because the indemnitee has met the applicable standard of conduct.

Section 145 further authorizes a corporation to purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation or enterprise, against any liability asserted against him and incurred by him in any such capacity, or arising out of his status as such, whether or not the corporation would otherwise have the power to indemnify him under Section 145. Also, Article VIII of the certificate of incorporation and Article VIII of the bylaws of Genesis Energy Finance Corporation provide for the indemnification of directors and officers of the company and such directors and officers who serve at the request of the company as directors, officers, employees or agents of any other enterprise against certain liabilities under certain circumstances.

Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers or persons controlling our company as set forth above, we have been informed that in the opinion of the Commission such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

provided, however, that paragraphs (a)(1)(i), (a)(1)(ii) and (a)(1)(iii) do not apply if information required to be included in a post-effective amendment by those paragraphs is contained in the reports filed with or furnished to the Commission by the registrant pursuant to section 13 or section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

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(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(5) That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933 each filing of the registrant’s annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the undersigned Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Houston, in the State of Texas, on July 6, 2015.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities set forth below on July 6, 2015.