AMENDMENT NO. 2 TO NOTE PURCHASE AGREEMENT

Exhibit 10.3

EXECUTION VERSION

AMENDMENT NO. 2 TO NOTE PURCHASE AGREEMENT

THIS AMENDMENT NO. 2 TO NOTE PURCHASE AGREEMENT (this “ Amendment ”), dated effective as of June 12, 2008, is between GMX Resources Inc., an Oklahoma corporation (the “ Company ”), and the noteholder listed on the signature page hereto (the “ Noteholder ”).

A. The Company and the Noteholder entered into a Note Purchase Agreement dated as of July 31, 2007, as amended by that certain Amendment No. 1 to Note Purchase Agreement and Limited Consent dated February 11, 2008 (as so amended, modified, restated, supplemented, renewed, extended, increased, rearranged and/or substituted from time to time, the “ Note Agreement ”). Capitalized terms used and not otherwise defined herein shall have the meanings ascribed to them in the Note Agreement.

B. Reference is made to the Subordinated Guaranty Agreement (the “ Guaranty Agreement ”) dated as of July 31, 2007, entered into by Endeavor Pipeline Inc., an Oklahoma corporation (“ Endeavor ”), and Diamond Blue Drilling Co., an Oklahoma corporation (“ Diamond ”, and together with Endeavor, the “ Subsidiary Guarantors ”).

C. The Company has requested that the Noteholder agree to (i) exclude the amounts determined as the mark-to-market values of Swaps, (ii) modify the calculation period for the current Total Debt to EBITDA financial test from a four-quarter test to a rolling twelve-month test, and (iii) amend the Note Agreement as more fully described hereinbelow.

D. The Noteholder is willing to agree to such amendments, subject to the performance and observance in full of each of the covenants, terms and conditions, and in reliance upon all of the representations and warranties of the Company, set forth herein.

NOW, THEREFORE, in consideration of the premises and the covenants, terms, conditions, representations and warranties herein contained, the parties hereto hereby agree as follows:

Section 1. AMENDMENTS TO NOTE AGREEMENT. Subject to the covenants, terms and conditions set forth herein and in reliance upon the representations and warranties of the Company herein contained, the Company and the Noteholder hereby agree to amend the Note Agreement as set forth below, effective as of the Amendment Effective Date (as hereinafter defined):

(a)  Existing Defined Terms. The following defined terms in paragrgaph 10B of the Note Agreement are hereby amended as follows:

(i) The defined term “ Adjusted PV10 ” is hereby amended by (1) deleting each occurrence of the words “clause (v) of paragraph 5A” and (2) replacing such clause in its entirety with the words “clause (vi) of paragraph 5A” in lieu of each occurrence thereof.

(ii) The defined term “ Engineer ” is hereby amended by (1) deleting each occurrence of the words “clause (v)” and (2) replacing such words in their entirety with the words “clause (vi)” in lieu of each occurrence thereof.

(iii) The defined term “ Indebtedness ” is hereby amended by (1) deleting clause “(vi)” thereof and (2) replacing such clause in its entirety with the following:

“(vi) the aggregate Swap Termination Value (provided that for the purpose of this definition only, clause (ii) of the definition of Swap Termination Value shall not apply) of all Swaps of such Person; and”

(b) New Covenant.

(i)  Paragraph 5A . Paragraph 5A is hereby amended by inserting the following new clause “(i)” and punctuation, renumbering existing clauses “(i)” through “(xiv)” as clauses “(ii)” through “(xv)”, respectively.

“(i) as soon as available and in any event within 45 days after the end of each month in each fiscal year, a certificate setting forth covenant calculations demonstrating compliance with paragraph 6A(2), all in reasonable detail and certified by an authorized financial officer of the Company, subject to changes from year-end adjustments;”

(c) Existing Covenants.

(i)  Paragraph 5A . The penultimate paragraph of paragraph 5A is hereby amended by deleting the words “clauses (i) and (ii)” occurring in the first sentence thereof and replacing such words in their entirety with the words “clauses (ii) or (iii)”.

(ii)  Paragraph 5A . The penultimate sentence of the penultimate paragraph of paragraph 5A is hereby amended by deleting the words “clause (ii)” occurring therein and replacing such words in their entirety with the words “clause (iii)”.

(iii)  Paragraph 5L . Paragraph 5L is hereby amended by deleting each occurrence of the words “clause (v) of paragraph 5A”