SIXTH AMENDMENT TO CREDIT AGREEMENT

Exhibit 10.1

EXECUTION VERSION

SIXTH AMENDMENT TO CREDIT AGREEMENT

     This SIXTH AMENDMENT TO CREDIT AGREEMENT (this “ Amendment ”) is dated as of September 30, 2009, among GASCO ENERGY, INC. (“ Borrower ”), CERTAIN SUBSIDIARIES OF BORROWER, as Guarantors (the “ Guarantors ”), the LENDERS party hereto (the “ Lenders ”), and JPMORGAN CHASE BANK, N.A., as Administrative Agent (“ Administrative Agent ”). Unless the context otherwise requires or unless otherwise expressly defined herein, capitalized terms used but not defined in this Amendment have the meanings assigned to such terms in the Credit Agreement (as defined below).

WITNESSETH:

      WHEREAS , the Borrower, the Guarantors, the Administrative Agent and the Lenders have entered into that certain Credit Agreement dated as of March 29, 2006 (as the same has been and may hereafter be amended, restated, supplemented or otherwise modified from time to time, the “ Credit Agreement ”); and

      WHEREAS, the Borrower, the Guarantors, the Administrative Agent and the Lenders desire to amend the Credit Agreement as provided herein upon the terms and conditions set forth herein.

      NOW, THEREFORE , for and in consideration of the mutual covenants and agreements herein contained and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged and confessed, the Borrower, the Guarantors, the Lenders and the Administrative Agent hereby agree as follows:

SECTION 1. Amendments to Credit Agreement. Subject to the satisfaction or waiver in writing of each condition precedent set forth in Section 2 of this Amendment, and in reliance on the representations, warranties, covenants and agreements contained in this Amendment, the Credit Agreement shall be amended in the manner provided in this Section 1 effective as of the date Borrower satisfies the conditions set forth in Section 2 of this Amendment.

      1.1 Mandatory Prepayment of Loans. Clause (a) of Section 2.10 of the Credit Agreement shall be and it hereby is amended and restated in its entirety to read as follows:

      (a) Except as otherwise provided in Section 2.10(b), in the event a Borrowing Base Deficiency exists, the Borrower shall, within thirty (30) days (or in the case of a Borrowing Base Deficiency arising from or related to the Scheduled Redetermination of the Borrowing Base on or about November 1, 2009, within fifteen (15) days) after written notice from the Administrative Agent to the Borrower of such Borrowing Base Deficiency, notify the Administrative Agent which of the following actions it will take to eliminate such Borrowing Base Deficiency and within sixty (60) days (or in the case of a Borrowing Base Deficiency arising from or related to the Scheduled Redetermination of the Borrowing Base on or about November 1, 2009, within thirty (30) days) after such notice from the Administrative Agent (a) by instruments satisfactory in form and substance to the Required Lenders, provide the Lenders with additional security consisting of Oil and Gas Interests with value and quality satisfactory to

the Lenders in their sole discretion to eliminate such Borrowing Base Deficiency, (b) prepay, without premium or penalty, the principal amount of the Loans in an amount sufficient to eliminate such Borrowing Base Deficiency or (c) by a combination of such additional security and such prepayment eliminate such Borrowing Base Deficiency.

      1.2 Special Redeterminations. The first sentence of Section 3.03 of the Credit Agreement shall be and it hereby is amended and restated in its entirety to read as follows:

      In addition to Scheduled Redeterminations, (a) the Borrower shall be permitted to request a Special Redetermination of the Borrowing Base once between each Scheduled Redetermination and (b) the Required Lenders shall be permitted to request a Special Redetermination of the Borrowing Base once between each Scheduled Redetermination.

SECTION 2. Conditions. The amendments to the Credit Agreement contained in Section 1 of this Amendment shall be effective upon the satisfaction of each of the conditions set forth in this Section 2 .

      2.1 Execution and Delivery. Each Credit Party, the Required Lenders and the Administrative Agent shall have executed and delivered this Amendmen