Substituted And Replaced First Amdmt. To The Exploration And Development Agrmt.

Exhibit 10.24

Chief James R. Gray

Osage Nation

P.O. Box 779

Pawhuska OK, 74056

Dear Chief Gray: Please consider this letter to be approval on the part of the Bureau of Indian Affairs (" BIA" ), for the Exploration and Development Agreement dated October 18, 2006, between the Osage Nation and Amvest Osage, Inc. (Amvest). The Effective Date of this agreement is October 18, 2006) which is the day the Agreement was approved by the Osage Minerals Council. This approval is made under authority granted in 25 CFR Part 226.2(f) which says in part " A contract may be entered into through competitive bidding as outlined in Section 22.6(b), negotiation, or a combination of both. . ." and " . . .The Superintendent may approve any such contract made by the Osage Tribal Council."

We hope that this agreement results in a long and mutually profitable relationship between the principals, and wish both parties good fortune.

Please direct any questions concerning this correspondence to Charles Hurlburt, Supervisory Petroleum Engineer at (918) 287-5710. Sincerely,

Superintendent

Similar Letter Sent to Jewell Purcell, Chairperson, Osage Minerals Council

SUBSTITUTED AND REPLACED FIRST AMENDMENT TO

THE EXPLORATION AND DEVELOPMENT AGREEMENT

THIS SUBSTITUTED AND REPLACED FIRST AMENDMENT TO THE EXPLORATION AND DEVELOPMENT AGREEMENT (the " Substituted and Replaced First Amendment" ), dated this 18 th day of October, 2006, by and between THE OSAGE NATION, as represented by the Osage Minerals Council (the " Council" ) in accordance with the Act of June 28, 1906 (34 Stat. 539), as amended, (the " Osage" ), by Ms. Jewell Purcell, Chairperson of the Council, under authority of Resolution No. of the Council, dated October 18, 2006, and AMVEST OSAGE, INC., a Virginia corporation, (" AMVEST" ). The Osage and AMVEST are collectively referred to as the " Parties" and individually referred to as a " Party." Recitals

WHEREAS, by Exploration and Development Agreement dated July 25, 2005, between the Osage and AMVEST under authority of Resolution No. 31-1196 of the Osage Tribal Council dated July 25, 2005, (the " Exploration and Development Agreement" or the " Agreement" ), the Osage granted certain exclusive rights to AMVEST for the leasing, exploration and development of portions of the Osage Mineral Estate with the goal of increasing production from the Osage Mineral Estate; and

WHEREAS, the Osage and AMVEST entered into that certain First Amendment to Exploration and Development Agreement, dated June 21, 2006, under authority of Resolution No. 31-1686 of the Osage Tribal Council dated June 21, 2006 (the " First Amendment" ); and

WHEREAS, the responsibility and power to administer and develop the Osage Mineral Estate vest with the Council pursuant to Section 4 of Article XV of the Osage Nation Constitution signed May 6, 2006; and WHEREAS, the Osage and AMVEST subsequently agreed to substitute and replace the First Amendment, under authority of Resolution No. 1-13 of the Council dated July 28, 2006, and further agreed on September 20, 2006 not to provide AMVEST the right to exchange (at no cost) the Red Rock Undeveloped Leases, as hereinafter defined, for other Coalbed Methane leases within the Osage Mineral Estate; and

WHEREAS, the Osage and Red Rock Exploration, LLC (" RRE" ) entered into that certain Exploration and Development Agreement, dated March 14, 2004, (the " Red Rock Concession Agreement" ), which, because of RRE' s lack of success and resulting failure to satisfy the drilling commitment thereunder, expired under its own terms; and

WHEREAS, AMVEST has demonstrated that it is technically, operationally and financially capable of successfully developing Coalbed Methane on the Osage Mineral Estate under the Exploration and Development Agreement and, therefore, desires to expand the Available Acreage for the mutual benefit of the Osage and AMVEST; and WHEREAS, AMVEST desires to incorporate into the Exploration and Development Agreement for leasing and development, the Coalbed Methane development rights associated

with acreage relinquished by RRE as a result of the Osage' s termination of the Red Rock Concession Agreement (the " Red Rock Relinquished Acreage" ); and

WHEREAS, AMVEST acquired, effective July 1, 2006, certain remaining developed and undeveloped leasehold and other assets of RRE and its affiliate, Copperhead Gathering, LLC, (collectively " Red Rock" ), originally acquired and/or developed by Red Rock on the Osage Mineral Estate in conjunction with the Red Rock Concession Agreement (the " Red Rock Assets" ); and

WHEREAS, the Osage and AMVEST acknowledge and agree that the Substituted and Replaced First Amendment is intended to enhance the rights and interests of the Osage Mineral Estate royalty interest holders; and

WHEREAS, the Osage and AMVEST now desire to amend the terms and conditions of the Exploration and Development Agreement by deleting the First Amendment in its entirety and replacing it with the following, which shall constitute the Substituted and Replaced First Amendment. NOW, THEREFORE, in consideration of Ten Dollars ($10.00), the mutual covenants contained herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Osage and AMVEST do hereby covenant and agree to substitute and replace the First Amendment in its entirety, as follows:

Agreement

1. The Osage and AMVEST hereby incorporate into the Available Acreage the Red Rock Relinquished Acreage consisting of approximately 112,480 acres (703 quarter-section tracts, as described on Exhibit " A-2" ). The Red Rock Relinquished Acreage shall be considered Available Acreage under the Agreement, as depicted on the Exhibit " A-5" map, and the Area of Interest shall, accordingly, be enlarged to include the acreage within the heavy black boundary line on the Exhibit " A-5" map, as more particularly set forth below. AMVEST shall pay the $4.00/acre Advance Option Payment to convert the Red Rock Relinquished Acreage to Licensed Acreage (from time-to-time as elected by AMVEST).

2.

The Osage hereby approve and support AMVEST' s and NSE' s acquisition of the Red Rock Assets, approve the assignment of the Red Rock Assets from Red Rock to AMVEST and NSE, and shall instruct the BIA to process such assignments. The Red Rock Assets consist of: (i) Coalbed Methane leases and Coalbed Methane, oil and/or gas leases on the Osage Mineral Estate acquired by Red Rock, on which Red Rock owned and operated wells (the " Red Rock Active Leases" ), consisting of 9,120 acres (57 quarter-section leases, as described on Exhibit " A-3" ); (ii) undeveloped Coalbed Methane leases on the Osage Mineral Estate acquired by Red Rock by payment to the Osage of the required advance option payment and lease bonus consideration pursuant to the Red Rock Concession Agreement (the " Red Rock Undeveloped Leases" ), consisting of 33,440 acres (209 quarter-section leases, as described on Exhibit " A-4" ); (iii) wells owned and operated by Red Rock on the Red Rock Active Leases; (iv) surface and subsurface


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production equipment; (v) pipelines and other gas and water production facilities and infrastructure, and (vi) other real and personal property and equipment. The Parties acknowledge and agree that the Red Rock Active Leases are in full force and effect, and that the terms and conditions of the Red Rock Active Leases shall remain unchanged. 3. The Parties agree that AMVEST may not exchange the Red Rock Undeveloped Leases for other Coalbed Methane leases identified as Available Acreage on the Exhibit " A-5" map; provided, however, in the event any of the Red Rock Undeveloped Leases expires or is terminated, said lease shall be considered Available Acreage and subject to the terms of the Exploration and Development Agreement. 4. Sections 1(d), 1(e), 1(k), 1(1), 1(m), 1(o), 1(s), 1(t), 1(u) and 1(v) of the Exploration and Development Agreement shall be deleted in their entirety and replaced with the following:

(d) Area of Interest" shall mean all of the property on the Osage Mineral Estate in northeast Oklahoma identified and depicted within the heavy black boundary line on the maps marked Exhibit " A" and Exhibit " A-5," within which the following are located: (i) Existing Licensed Acreage comprised of 190,000 acres, (ii) Licensed Acreage added by AMVEST during the first year of Phase I consisting of 15,040 acres, (iii) Additional Licensed Acreage (as hereinafter defined) comprised of 42,560 acres, (iv) the Available Acreage (specifically including the Red Rock Relinquished Acreage) from which AMVEST may select the Phase I Acreage, the Phase II Acreage, the Phase III Acreage and the Phase IV Acreage; and (v) the Excluded Acreage. (e) " Available Acreage" shall mean the acreage within the Area of Interest depicted on Exhibit " A" and Exhibit " A-5," and more precisely described on Exhibit " A-1," and Exhibit " A-2," which is subject to this Agreement and from which AMVEST may select the Phase I Acreage, the Phase II Acreage, the Phase III Acreage and the Phase IV Acreage.

(k) " Exhibit " A-1" shall mean that schedule attached hereto and made a part hereof, consisting of 17 pages, which, as of the Effective Date of the Agreement, sets forth the acreage descriptions of the Existing Licensed Acreage and the Available Acreage.

" Exhibit A-2" shall mean that schedule attached hereto and made a part hereof, consisting of 4 pages, which, as of the effective date of the Substituted and Replaced First Amendment, sets forth the acreage descriptions of the property rights relinquished by Red Rock pursuant to the Red Rock Concession Agreement which expired under its own terms (the Red Rock Relinquished Acreage), consisting of 112,480 acres (703 quarter-section tracts). " Exhibit A-3" shall mean that schedule attached hereto and made a part hereof, consisting of 1 page, which, as of the effective date of the Substituted and Replaced First Amendment, sets forth the acreage descriptions of the leases previously acquired by Red Rock and either active or held by production (the Red Rock Active Leases), and


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subsequently purchased by AMVEST, consisting of 9,120 acres (57 quarter-section leases). " Exhibit A-4" shall mean that schedule attached hereto and made a part hereof, consisting of 2 pages, which, as of the effective date of the Substituted and Replaced First Amendment, sets forth the acreage descriptions of the undeveloped leases recently acquired by Red Rock (the Red Rock Undeveloped Leases), and subsequently purchased by AMVEST, consisting of 33,440 acres (209 quarter-section leases).

" Exhibit A-5" shall mean that map or plat attached hereto and made a part hereof which, as of the effective date of the Substituted and Replaced First Amendment, represents properties previously controlled by Red Rock pursuant to the Red Rock Concession Agreement, and depicts: (i) the addition of lands to the Exhibit " A" Area of Interest, (ii) the addition of lands to the Exhibit " A" Licensed Acreage, (iii) the addition of lands to the Exhibit " A" Available Acreage, and (iv) the addition of lands to the Exhibit " A" Excluded Acreage.

(l) " Existing Licensed Acreage" shall mean the initial 190,000 acres of land depicted on Exhibit " A," and more precisely described on Exhibit " A-1," which has previously been identified and accepted by the Parties prior to the Effective Date of the Agreement, and which was subsequently increased by an additional 15,040 acres of Licensed Acreage during the first year of Phase I.

" Additional Licensed Acreage" shall mean the 42,560 acres of land (9,120 acres of Red Rock Active Leases, plus 33,440 acres of Red Rock Undeveloped Leases) depicted on Exhibit " A-5," and more precisely described on Exhibit " A-3" and Exhibit " A-4," which have previously been identified and accepted by the Parties prior to the effective date of the Substituted and Replaced First Amendment.

(m) " Horizontal Well" shall mean: (i) any drilling or jetting of a horizontal or near- horizontal lateral into a potentially-productive interval (whether into a coal seam or non- coal formation) from a vertical or slant wellbore including, but not limited to, the drilling or jetting of a long-, medium- or short-radius lateral (as such terms are commonly used in the industry), the long axis of which lateral is oriented approximately parallel to the bedding plane of the formation being drilled into, or (ii) a directionally-drilled, high-angle reach or slant well that requires the use of directional drilling services to (x) access gas or oil resources that may not easily or cost-effectively be accessed from a surface location (i.e., under housing or recreational developments, bodies of water, highways, topographic constraints., etc.), or (y) improve reservoir drainage and/or development economics.

(o) " Licensed Acreage' shall mean the Existing Licensed Acreage, the 15,040 acres of Licensed Acreage added during the first year of Phase I, the Additional Licensed Acreage, the Phase I Acreage (when and if added), the Phase II Acreage (when and if added), the Phase III Acreage (when and if added), the Phase IV Acreage (when and if added), the Excluded Acreage (when and if added), and the remaining Available Acreage (when and if added), for which AMVEST has the exclusive right to enter into th ...