Underwriting Agreement relating to the Notes

DELTA PETROLEUM CORPORATION

$100,000,000 3.75% Convertible Senior Notes due 2037

Underwriting Agreement

April 19, 2007

J.P. Morgan Securities Inc.
Lehman Brothers Inc.
Deutsche Bank Securities Inc.
  As Representatives of the several
  Underwriters listed in Schedule 1 hereto
c/o J.P. Morgan Securities Inc.
277 Park Avenue
New York, New York 10172

Ladies and Gentlemen:

     Delta Petroleum Corporation, a Delaware corporation (the “Company”), proposes to issue and sell to the several Underwriters listed in Schedule 1 hereto (the “Underwriters”), for whom you are acting as representatives (the “Representatives”), $100,000,000 principal amount of its 3.75% Convertible Senior Notes due 2037 (the “Firm Securities”) and, at the option of the Underwriters, up to an additional $15,000,000 principal amount of its 3.75% Convertible Senior Notes due 2037 (the “Additional Securities” and, together with the Firm Securities, the “Securities”). The Securities will be issued pursuant to an Indenture (the “Indenture”), to be dated as of the Closing Date (as defined in Section 2(c)), among the Company, the subsidiaries listed in Schedule 2 hereto (the “Guarantors”) and U.S. Bank National Association, as trustee (the “Trustee”), and will be guaranteed on an unsecured senior basis by each of the Guarantors (the “Guarantees”).

     The Securities will be convertible into fully paid, nonassessable shares of common stock of the Company, par value $0.01 per share (the “Common Stock”), on the terms, and subject to the conditions, set forth in the Indenture. As used herein, “Conversion Shares” means the shares of Common Stock issuable upon conversion of the Securities.

     The Company and the Guarantors hereby confirm their agreement with the several Underwriters concerning the purchase and sale of the Securities, as follows:

     1. Registration Statement. The Company and the Guarantors have prepared and filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Securities Act”), a registration statement on Form S-3 (File No. 333-142180) including a prospectus, relating to the Securities. Such registration statement, as amended at the time it becomes effective, including the information, if any, deemed pursuant to Rule 430A, 430B or 430C under the Securities Act to be part of the registration statement at the time of its effectiveness (“Rule 430 Information”), is referred to herein as the “Registration Statement”; and as used herein, the term “Preliminary Prospectus” means each prospectus included in such

registration statement (and any amendments thereto) before it becomes effective, any prospectus filed with the Commission pursuant to Rule 424(a) under the Securities Act and the prospectus included in the Registration Statement at the time of its effectiveness that omits Rule 430 Information, and the term “Prospectus” means the prospectus in the form first used (or made available upon request of purchasers pursuant to Rule 173 under the Securities Act) in connection with confirmation of sales of the Securities. If the Company and the Guarantors have filed an abbreviated registration statement pursuant to Rule 462(b) under the Securities Act (the “Rule 462 Registration Statement”), then any reference herein to the term “Registration Statement” shall be deemed to include such Rule 462 Registration Statement. Any reference in this Agreement to the Registration Statement, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act, as of the effective date of the Registration Statement or the date of such Preliminary Prospectus or the Prospectus, as the case may be, and any reference to “amend”, “amendment” or “supplement” with respect to the Registration Statement, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any documents filed after such date under the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Exchange Act”) that are deemed to be incorporated by reference therein. Capitalized terms used but not defined herein shall have the meanings given to such terms in the Registration Statement and the Prospectus.

     At or prior to the time when sales of the Securities were first made (the “Time of Sale”), the Company had prepared the following information (collectively, the “Time of Sale Information”): a prospectus dated April 17, 2007, as supplemented by a preliminary prospectus supplement dated April 17, 2007 relating to the Securities, and each “free-writing prospectus” (as defined pursuant to Rule 405 under the Securities Act) listed on Annex B hereto.

     2. Purchase of the Securities by the Underwriters. (a) The Company agrees to issue and sell the Firm Securities to the several Underwriters as provided in this Agreement, and each Underwriter, on the basis of the representations, warranties and agreements set forth herein and subject to the conditions set forth herein, agrees, severally and not jointly, to purchase from the Company the respective principal amount of Firm Securities set forth opposite such Underwriter’s name in Schedule 1 hereto at a price equal to 97.00% of the principal amount thereof plus accrued interest, if any, from April 25, 2007 to the Closing Date (as defined below) (the “Purchase Price”).

     In addition, the Company agrees to issue and sell the Additional Securities to the several Underwriters as provided in this Agreement, and the Underwriters, on the basis of the representations, warranties and agreements set forth herein and subject to the conditions set forth herein, shall have the option to purchase, severally and not jointly, from the Company the Additional Securities at the Purchase Price.

     If any Additional Securities are to be purchased, the principal amount of Additional Securities to be purchased by each Underwriter shall be the principal amount of Additional Securities which bears the same ratio to the principal amount of Additional Securities being purchased as the principal amount of Firm Securities set forth opposite the name of such Underwriter in Schedule 1 hereto (or such number increased as set forth in Section 10 hereof)

bears to the principal amount of Firm Securities being purchased from the Company by the several Underwriters, subject, however, to such adjustments to eliminate any fractional Securities as the Representatives in their sole discretion shall make.

     The Underwriters may exercise the option to purchase the Additional Securities at any time in whole, or from time to time in part, on or before the thirtieth day following the date of this Agreement, by written notice from the Representatives to the Company. Such notice shall set forth the aggregate principal amount of Additional Securities as to which the option is being exercised and the date and time when the Additional Securities are to be delivered and paid for which may be the same date and time as the Closing Date (as hereinafter defined) but shall not be earlier than the Closing Date nor later than the tenth full business day (as hereinafter defined) after the date of such notice (unless such time and date are postponed in accordance with the provisions of Section 10 hereof). Any such notice shall be given at least two business days prior to the date and time of delivery specified therein.

          (b) The Company and the Guarantors understand that the Underwriters intend to make a public offering of the Securities as soon after the effectiveness of this Agreement as in the judgment of the Representatives is advisable, and initially to offer the Securities on the terms set forth in the Prospectus. The Company and the Guarantors acknowledge and agree that the Underwriters may offer and sell Securities to or through any affiliate of an Underwriter and that any such affiliate may offer and sell Securities purchased by it to or through any Underwriter.

          (c) Payment for and delivery of the Firm Securities and the Guarantees shall be made at the offices of Simpson Thacher & Bartlett LLP at 10:00 A.M. New York City time on April 25, 2007, or at such other time or place on the same or such other date, not later than the fifth business day thereafter, as the Representatives and the Company may agree upon in writing or, in the case of the Additional Securities, on the date and at the time and place specified by the Representatives in the written notice of the Underwriters’ election to purchase such Additional Securities. The time and date of such payment for the Firm Securities is referred to herein as the “Closing Date” and the time and date for such payment for the Additional Securities, if other than the Closing Date, is herein referred to as the “Additional Closing Date.”

     Payment for the Securities shall be made by wire transfer in immediately available funds to the account specified by the Company to the Representatives against delivery to the nominee of The Depository Trust Company (“DTC”), for the account of the Underwriters, of one or more global notes representing the Firm Securities (collectively, the “Global Notes”), with any transfer taxes payable in connection with the sale of the Firm Securities duly paid by the Company. Payment for any Additional Securities shall be made on the Closing Date or the Additional Closing Date, as applicable, by wire transfer in immediately available funds to the account specified by the Company to the Representatives against delivery to the nominee of DTC, for the account of the Underwriters, of one or more Global Notes representing the Additional Securities, with any transfer taxes payable in connection with the sale of the Additional Securities duly paid by the Company. The Global Notes will be made available for inspection by the Representatives not later than 1:00 P.M., New York City time, on the business day prior to the Closing Date or the Additional Closing Date, as the case may be.

          (d) The Company and the Guarantors acknowledge and agree that the Underwriters are acting solely in the capacity of an arm’s length contractual counterparty to the Company and the Guarantors with respect to the offering of Securities, Guarantees and Conversion Shares contemplated hereby (including in connection with determining the terms of the offering) and not as financial advisors or fiduciaries to, or agents of, the Company, any Guarantor or any other person. Additionally, neither the Representatives nor any other Underwriter is advising the Company, any Guarantor or any other person as to any legal, tax, investment, accounting or regulatory matters in any jurisdiction. The Company and the Guarantors shall consult with their own advisors concerning such matters and shall be responsible for making their own independent investigation and appraisal of the transactions contemplated hereby, and neither the Representatives nor any other Underwriter shall have any responsibility or liability to the Company or any Guarantor with respect thereto. Any review by the Representatives or any other Underwriter of the Company, the Guarantors and the transactions contemplated hereby or other matters relating to such transactions will be performed solely for the benefit of the Underwriters and shall not be on behalf of the Company, the Guarantors or any other person.

     3. Representations and Warranties of the Company and the Guarantors. The Company and each of the Guarantors jointly and severally represent and warrant to each Underwriter that:

          (a) Preliminary Prospectus. No order preventing or suspending the use of any Preliminary Prospectus has been issued by the Commission, and each Preliminary Prospectus, at the time of filing thereof, complied in all material respects with the Securities Act and did not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company and the Guarantors make no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in any Preliminary Prospectus.

          (b) Time of Sale Information. The Time of Sale Information, at the Time of Sale did not, and at the Closing Date and as of the Additional Closing Date, as the case may be, will not, contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company and the Guarantors make no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in such Time of Sale Information. No statement of material fact included in the Prospectus has been omitted from the Time of Sale Information and no statement of material fact included in the Time of Sale Information that is required to be included in the Prospectus has been omitted therefrom.

          (c) Issuer Free Writing Prospectus. Other than the Preliminary Prospectus and the Prospectus, neither the Company nor any Guarantor (including their respective agents

          (e) Incorporated Documents. The documents incorporated by reference in the Registration Statement, the Prospectus or the Time of Sale Information, when they were filed with the Commission conformed in all material respects to the requirements of the Exchange Act and none of such documents contained any untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; and any further documents so filed and incorporated by reference in the Registration Statement, the Prospectus or the Time of Sale Information, when such documents are filed with the Commission, will conform in all material respects to the requirements of the Exchange Act and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

          (f) Financial Statements. The financial statements and the related notes thereto of the Company and its consolidated subsidiaries included or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus comply in all material respects with the applicable requirements of the Securities Act and the Exchange Act, as applicable, and present fairly in all material respects the financial position of the Company and its consolidated subsidiaries as of the dates indicated and the results of their operations and the changes in their cash flows for the periods specified; such financial statements have been prepared in conformity with generally accepted accounting principles applied on a consistent basis throughout the periods covered thereby; and the other financial information included or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus has been derived from the accounting records of the Company and its subsidiaries and presents fairly in all material respects the information shown thereby.

          (g) No Material Adverse Change. Since the date of the most recent financial statements of the Company included or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus, except in each case as otherwise disclosed in the Registration Statement, the Time of Sale Information and the Prospectus, (i) there has not been any change in the capital stock or long-term debt of the Company or any of its subsidiaries, or any dividend or distribution of any kind declared, set aside for payment, paid or made by the Company on any class of capital stock, or any material adverse change, or any development involving a prospective material adverse change, in or affecting the business, properties, management, financial position, stockholders’ equity, results of operations or prospects of the Company and its subsidiaries taken as a whole; (ii) neither the Company nor any of its subsidiaries has entered into any transaction or agreement that is material to the Company and its subsidiaries taken as a whole or incurred any liability or obligation, direct or contingent, that is material to the Company and its subsidiaries taken as a whole; and (iii) neither the Company nor any of its subsidiaries has sustained any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor disturbance or dispute or any action, order or decree of any court or arbitrator or governmental or regulatory authority.

          (h) Organization and Good Standing. The Company and each of its subsidiaries have been duly organized and are validly existing and in good standing under the laws of their respective jurisdictions of organization, are duly qualified to do business and are in

good standing in each jurisdiction in which their respective ownership or lease of property or the conduct of their respective businesses requires such qualification, and have all power and authority necessary to own or hold their respective properties and to conduct the businesses in which they are engaged, except where the failure to be so qualified or have such power or authority would not, individually or in the aggregate, have a material adverse effect on the business, properties, management, financial position, stockholders’ equity, results of operations or prospects of the Company and its subsidiaries taken as a whole or on the performance by the Company and the Guarantors of their obligations under the Securities, the Guarantees and the Conversion Shares (a “Material Adverse Effect”). The Company does not own or control, directly or indirectly, any corporation, association or other entity other than the entities listed in Annex A hereto (the “subsidiaries”).

          (i) Capitalization. The Company has an authorized capitalization as set forth in the Registration Statement, the Time of Sale Information and the Prospectus under the heading “Capitalization”; all the outstanding shares of capital stock of the Company have been duly and validly authorized and issued and are fully paid and non-assessable and are not subject to any pre-emptive or similar rights; except as described in or expressly contemplated by the Time of Sale Information and the Prospectus, there are no outstanding rights (including, without limitation, pre-emptive rights), warrants or options to acquire, or instruments convertible into or exchangeable for, any shares of capital stock or other equity interest in the Company or any of its subsidiaries, or any contract, commitment, agreement, understanding or arrangement of any kind relating to the issuance of any capital stock of the Company or any such subsidiary, any such convertible or exchangeable securities or any such rights, warrants or options; the capital stock of the Company conforms in all material respects to the description thereof contained in the Registration Statement, the Time of Sale Information and the Prospectus; and all the outstanding shares of capital stock or other equity interests of each subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and are owned directly or indirectly by the Company, free and clear of any lien, charge, encumbrance, security interest, restriction on voting or transfer or any other claim of any third party, except for (i) liens existing under the Amended and Restated Credit Agreement, dated November 17, 2006, by and among the Company, JPMorgan Chase Bank, N.A., as administrative agent, and each of the lenders thereto, as amended by the First Amendment to Amended and Restated Credit Agreement, dated December 4, 2006, by and among the Company, JPMorgan Chase Bank, N.A., as administrative agent, and each of the lenders thereto (together, the “Credit Agreement”) on the date hereof as set forth in the Registration Statement, the Time of Sale Information and the Prospectus, (ii) liens existing under the Credit Agreement, dated as of May 4, 2006 (the “DHS Credit Agreement”) among DHS Holding Company, DHS Drilling Company, and JPMorgan Chase Bank, N.A., as administrative agent, and each of the lenders thereto on the date hereof as set forth in the Registration Statement, the Time of Sale Information and the Prospectus and (iii) as set forth in Annex A and disclosed in the Registration Statement, the Time of Sale Information and the Prospectus.

          (j) Due Authorization. The Company and each of the Guarantors has requisite corporate (or other entity) right, power and authority to execute and deliver this Agreement, the Securities and the Indenture (including each Guarantee set forth therein) (collectively, the “Transaction Documents”), and the Company and each of the Guarantors have the requisite corporate (or other entity) right, power and authority to perform their respective

“controlled” by an “investment company” within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Investment Company Act”).

          (y) Taxes. The Company and its subsidiaries have paid all material federal, state, local and foreign taxes and filed all material tax returns required to be paid or filed through the date hereof; and except as otherwise disclosed in the Registration Statement, the Time of Sale Information and the Prospectus, there is no material tax deficiency that has been, or would reasonably be expected to be, asserted against the Company or any of its subsidiaries or any of their respective properties or assets.

          (z) Licenses and Permits. The Company and its subsidiaries possess all licenses, certificates, permits and other authorizations issued by, and have made all declarations and filings with, the appropriate federal, state, local or foreign governmental or regulatory authorities that are necessary for the ownership or lease of their respective properties or the conduct of their respective businesses as described in the Registration Statement, the Time of Sale Information and the Prospectus, except where the failure to possess or make the same would not, individually or in the aggregate, have a Material Adverse Effect; and except as described in the Registration Statement, the Time of Sale Information and the Prospectus, neither the Company nor any of its subsidiaries has received notice of any revocation or modification of any such license, certificate, permit or authorization or has any reason to believe that any such license, certificate, permit or authorization will not be renewed in the ordinary course.

          (aa) No Labor Disputes. No labor disturbance by or dispute with employees of the Company or any of its subsidiaries exists or, to the knowledge of the Company and each of the Guarantors, is contemplated or threatened and neither the Company nor any Guarantor is aware of any existing or imminent labor disturbance by, or dispute with, the employees of any of the Company’s or any of the Company’s subsidiaries’ principal suppliers, contractors or customers, except as would not have a Material Adverse Effect.

          (bb) Compliance with Environmental Laws. (i) The Company and its subsidiaries (x) are, and at all prior relevant times were, in compliance with any and all applicable federal, state, local and foreign laws, rules, regulations, requirements, decisions and orders relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (collectively, “Environmental Laws”); (y) have received and are in compliance with all permits, licenses, certificates or other authorizations or approvals required of them under applicable Environmental Laws to conduct their respective businesses; and (z) have not received notice of any actual or potential liability for the investigation or remediation of any disposal or release of hazardous or toxic substances or wastes, pollutants or contaminants, and (ii) there are no costs or liabilities associated with Environmental Laws of or relating to the Company or its subsidiaries, except for any such failure to comply, or failure to receive required permits, licenses or approvals, or cost or liability, as would not, individually or in the aggregate, have a Material Adverse Effect.

          (cc) Hazardous Substances. There has been no storage, generation, transportation, handling, treatment, disposal, discharge, emission, or other release of any kind of toxic wastes or hazardous substances, including, but not limited to, any naturally occurring

of any provision of the Foreign Corrupt Practices Act of 1977; or (iv) made any bribe, rebate, payoff, influence payment, kickback or other unlawful payment.

          (jj) Compliance with Money Laundering Laws. The operations of the Company and its subsidiaries are and have been conducted at all times in compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all jurisdictions, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Money Laundering Laws is pending or, to the knowledge of the Company, threatened.

          (kk) Compliance with OFAC. None of the Company, any of its subsidiaries or, to the knowledge of the Company, any director, officer, agent, employee or Affiliate of the Company or any of its subsidiaries is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. Department of the Treasury (“OFAC”); and the Company will not directly or indirectly use the proceeds of the offering of the Securities hereunder, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other person or entity, for the purpose of financing the activities of any person currently subject to any U.S. sanctions administered by OFAC.

          (ll) Solvency. On the Closing Date or the Additional Closing Date, as the case may be, and immediately after giving effect to the issuance of the Securities and the consummation of the other transactions related thereto (as described in the Registration Statement, Time of Sale Information and the Prospectus) the Company and the Guarantors, on a consolidated basis, will be Solvent. As used in this paragraph, the term “Solvent” means, with respect to a particular date, that on such date (i) the present fair market value (or present fair saleable value) of the assets of the Company and the Guarantors, on a consolidated basis, is not less than the total amount required to pay the probable liabilities of the Company and the Guarantors, on a consolidated basis, on their total existing debts and liabilities (including contingent liabilities) as they become absolute and matured; (ii) the Company and the Guarantors, on a consolidated basis, are able to realize upon their assets and pay their debts and other liabilities, contingent obligations and commitments as they mature and become due in the normal course of business; (iii) assuming consummation of the issuance of the Securities as contemplated by this Agreement, the Registration Statement, the Time of Sale Information and the Prospectus, the Company has not incurred, and does not propose to incur, debts or liabilities that would be beyond its ability to pay as such debts and other liabilities mature; (iv) the Company and the Guarantors, on a consolidated basis, are not engaged in any business or transaction, and do not propose to engage in any business or transaction, for which their property would constitute unreasonably small capital after giving due consideration to the prevailing practice in the industry in which the Company and the Guarantors are engaged; and (v) the Company or such Guarantor, as the case may be, is not a defendant in any civil action that would result in a judgment that the Company or such Guarantor, as the case may be, is or would become unable to satisfy.

          (mm) No Restrictions on Subsidiaries. No subsidiary of the Company is currently prohibited, directly or indirectly, under any agreement or other instrument to which it is a party or is subject, from paying any dividends to the Company, from making any other distribution on such subsidiary’s capital stock, from repaying to the Company any loans or advances to such subsidiary from the Company or from transferring any of such subsidiary’s properties or assets to the Company or any other subsidiary of the Company, except pursuant to the Credit Agreement, the DHS Credit Agreement, and the Indenture dated as of March 15, 2005 (the “2005 Indenture”), among Delta Petroleum Corporation, the guarantors named therein and U.S. Bank National Association, as trustee, relating to the Company’s 7% Senior Notes due 2015.

          (nn) No Broker’s Fees. Neither the Company nor any of its subsidiaries is a party to any contract, agreement or understanding with any person (other than this Agreement) that would give rise to a valid claim against the Company or any of its subsidiaries or any Underwriter for a brokerage commission, finder’s fee or like payment in connection with the offering and sale of the Securities.

          (oo) No Registration Rights. Except for rights with respect to shares that have been registered for resale pursuant to effective registration statements as described in the Registration Statement, the Time of Sale Information and the Prospectus, no person has the right to require the Company or any of its subsidiaries to register any securities for sale under the Securities Act by reason of the filing of the Registration Statement with the Commission or the issuance and sale of the Securities.

          (pp) No Stabilization. Neither the Company nor any Guarantor has taken, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in any stabilization or manipulation of the price of the Securities.

          (qq) Business with Cuba. The Company has complied with all provisions of Section 517.075, Florida Statutes (Chapter 92-198, Laws of Florida) relating to doing business with the Government of Cuba or with any person or affiliate located in Cuba.

          (rr) Margin Rules. Neither the issuance, authentication, sale and delivery of the Securities and the Guarantees nor the application of the proceeds thereof by the Company as described in the Registration Statement, the Time of Sale Information and the Prospectus will violate Regulation T, U or X of the Board of Governors of the Federal Reserve System or any other regulation of such Board of Governors.

          (ss) Forward-Looking Statements. No forward-looking statement (within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act) contained in the Registration Statement, the Time of Sale Information and the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith.

          (tt) Statistical and Market Data. Nothing has come to the attention of the Company that has caused the Company to believe that the statistical and market-related data included in the Registration Statement, the Time of Sale Information and the Prospectus is not based on or derived from sources that are reliable and accurate in all material respects.

          (uu) Reserve Report Data. The oil and gas reserve estimates of the Company and its subsidiaries for the years ended June 30, 2003 and 2004, the six months ended December 31, 2005 and the year ended December 31, 2006 contained in the Registration Statement, the Time of Sale Information and the Prospectus are derived from reports that have been prepared by independent petroleum consulting firms as set forth in the Registration Statement, the Time of Sale Information and the Prospectus, to the Company’s knowledge, such reserve estimates fairly reflect the oil and gas reserves of the Company and its subsidiaries at the dates indicated in the Registration Statement, the Time of Sale Information and the Prospectus and were prepared in accordance with the Commission guidelines applied on a consistent basis throughout the periods involved.

          (vv) Independent Reserve Engineering Firms. Ralph E. Davis Associates, Inc. and Mannon Associates are each independent reserve engineers with respect to the Company and its subsidiaries and for the periods set forth in the Registration Statement, the Time of Sale Information and the Prospectus.

          (ww) Sarbanes-Oxley Act. There is and has been no failure on the part of the Company or any of the Company’s directors or officers, in their capacities as such, to comply in all material respects with any provision of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith, including Section 402 related to loans and Sections 302 and 906 related to certifications.

          (xx) Status under the Securities Act. The Company is not an “ineligible issuer” and is a “well-known seasoned issuer,” in each case as defined under the Securities Act, in each case at the times specified in the Securities Act in connection with the offering of the Securities. The Company has paid the registration fee for this offering pursuant to Rule 456(b)(1) under the Securities Act or will pay such fees within the time period required by such rule (without giving effect to the proviso therein) and in any event prior to the Closing Date.

          (yy) Beneficial Owners. To the Company’s knowledge, the Company has no beneficial owner (as defined in Rules 13d-3 and 13d-5 under the Exchange Act) of more than 5% of its Common Stock other than as set forth in the Company’s Proxy Statement on Schedule 14A filed with the Commission on December 28, 2006.

     4. Further Agreements of the Company and the Guarantors. The Company and each of the Guarantors jointly and severally covenants and agrees with each Underwriter that:

          (a) Required Filings. The Company and the Guarantors will file the final Prospectus with the Commission within the time periods specified by Rule 424(b) and Rule 430A, 430B or 430C under the Securities Act, will file any Issuer Free Writing Prospectus (including the Term Sheet in the form of Annex C hereto) to the extent required by Rule 433 under the Securities Act; and will file promptly all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of the Prospectus and for so long as the delivery of a prospectus is required in connection with the offering or sale of the Securities; and the Company will furnish copies of the Prospectus and each Issuer Free Writing Prospectus (to the extent not previously delivered) to the Underwriters in New York City

prior to 10:00 A.M., New York City time, on the business day next succeeding the date of this Agreement in such quantities as the Representatives may reasonably request. The Company will pay the registration fees for this offering within the time period required by Rule 456(b)(i) under the Securities Act prior to the Closing Date.

          (b) Delivery of Copies. The Company will deliver, without charge, (i) to the Representatives, three signed copies of the Registration Statement as originally filed and each amendment thereto, in each case including all exhibits and consents filed therewith and documents incorporated by reference therein; and (ii) to each Underwriter (A) a conformed copy of the Registration Statement as originally filed and each amendment thereto (without exhibits) and (B) during the Prospectus Delivery Period (as defined below), as many copies of the Prospectus (including all amendments and supplements thereto and documents incorporated by reference therein) and each Issuer Free Writing Prospectus as the Representatives may reasonably request. As used herein, the term “Prospectus Delivery Period” means such period of time after the first date of the public offering of the Securities as in the opinion of counsel for the Underwriters a prospectus relating to the Securities is required by law to be delivered (or required to be delivered but for Rule 172 under the Securities Act) in connection with sales of the Securities by any Underwriter or dealer.

          (c) Amendments or Supplements, Issuer Free Writing Prospectuses. Before preparing, using, authorizing, approving, referring to or filing any Issuer Free Writing Prospectus, and before filing any amendment or supplement to the Registration Statement or the Prospectus, the Company will furnish to the Representatives and counsel for the Underwriters a copy of the proposed Issuer Free Writing Prospectus, amendment or supplement for review and will not prepare, use, authorize, approve, refer to or file any such Issuer Free Writing Prospectus or file any such proposed amendment or supplement to which the Representatives reasonably object.

          (d) Notice to the Representatives. The Company will advise the Representatives promptly, and confirm such advice in writing, (i) when any amendment to the Registration Statement has been filed or becomes effective; (ii) when any supplement to the Prospectus or any Issuer Free Writing Prospectus or any amendment to the Prospectus has been filed; (iii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or the receipt of any comments from the Commission relating to the Registration Statement or any other request by the Commission for any additional information; (iv) of the issuance by the Commission of any order suspending the effectiveness of the Registration Statement or preventing or suspending the use of any Preliminary Prospectus, the Time of Sale Information or the Prospectus or the initiation or threatening of any proceeding for that purpose or pursuant to Section 8A of the Securities Act; (v) of the occurrence of any event within the Prospectus Delivery Period as a result of which the Prospectus, the Time of Sale Information or any Issuer Free Writing Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus, the Time of Sale Information or any such Issuer Free Writing Prospectus is delivered to a purchaser, not misleading; (vi) of the receipt by the Company of any notice of objection of the Commission to the use of the Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) under the

Securities Act; and (vii) of the receipt by the Company of any notice with respect to any suspension of the qualification of the Securities for offer and sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose; and the Company will use its best efforts to prevent the issuance of any such order suspending the effectiveness of the Registration Statement, preventing or suspending the use of any Preliminary Prospectus, the Time of Sale Information or the Prospectus or suspending any such qualification of the Securities and, if any such order is issued, will obtain as soon as possible the withdrawal thereof.

     (e) Ongoing Compliance. (1) If during the Prospectus Delivery Period (i) any event shall occur or condition shall exist as a result of which the Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, not misleading or (ii) it is necessary to amend or supplement the Prospectus to comply with law, the Company will immediately notify the Underwriters thereof and forthwith prepare and, subject to paragraph (c) above, file with the Commission and furnish to the Underwriters and to such dealers as the Representatives may designate, such amendments or supplements to the Prospectus as may be necessary so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, be misleading or so that the Prospectus will comply with law and (2) if at any time prior to the Closing Date (i) any event shall occur or condition shall exist as a result of which the Time of Sale Information as then amended or supplemented would include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances existing when the Time of Sale Information is delivered to a purchaser, not misleading or (ii) it is necessary to amend or supplement the Time of Sale Information to comply with law, the Company will immediately notify the Underwriters thereof and forthwith prepare and, subject to paragraph (c) above, file with the Commission (to the extent required) and furnish to the Underwriters and to such dealers as the Representatives may designate, such amendments or supplements to the Time of Sale Information as may be necessary so that the statements in the Time of Sale Information as so amended or supplemented will not, in the light of the circumstances existing when the Time of Sale Information is delivered to a purchaser, be misleading or so that the Time of Sale Information will comply with law.

     (f) Blue Sky Compliance. The Company will qualify the Securities for offer and sale under the securities or Blue Sky laws of such jurisdictions as the Representatives shall reasonably request and will continue such qualifications in effect so long as required for distribution of the Securities; provided that neither the Company nor any of the Guarantors shall be required to (i) qualify as a foreign corporation or other entity or as a dealer in securities in any such jurisdiction where it would not otherwise be required to so qualify, (ii) file any general consent to service of process in any such jurisdiction or (iii) subject itself to taxation in any such jurisdiction if it is not otherwise so subject.

     (g) Earning Statement. The Company will make generally available to its security holders and the Representatives as soon as practicable an earning statement that satisfies the provisions of Section 11(a) of the Securities Act and Rule 158 of the Commission promulgated thereunder covering a period of at least twelve months beginning with the first

fiscal quarter of the Company occurring after the “effective date” (as defined in Rule 158) of the Registration Statement.

          (h) Clear Market. Except as provided in Section 4(i), during the period from the date hereof through and including the date that is 90 days after the date hereof, the Company and each of the Guarantors will not, without the prior written consent of J.P. Morgan Securities Inc., offer, sell, contract to sell or otherwise dispose of any debt securities issued or guaranteed by the Company or any of the Guarantors and having a tenor of more than one year.

          (i) Clear Market. For a period of 90 days after the date of the initial public offering of the Securities, the Company will not (i) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock or (ii) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise, without the prior written consent of the Representatives, other than (i) the Securities to be sold hereunder, (ii) the sale of the Company’s Common Stock to the underwriters therefor in the Company’s concurrent and separate Common Stock offering, (iii) any shares of Common Stock of the Company issued upon the exercise of options granted under existing employee stock option plans, (iv) 1,500,000 shares of Common Stock to be issued pursuant to the Company’s 2007 Performance and Equity Incentive Plan (the “2007 Incentive Plan”) to the Company’s executive officers as contemplated by the Company’s Proxy Statement on Schedule 14A filed December 28, 2006, which shares of Common Stock will be subject to the lock-up agreements described in Section 6(p), and (v) up to 1,300,000 additional shares of Common Stock of the Company issuable under the Company’s 2007 Incentive Plan, which was approved by the Company’s stockholders on January 29, 2007. Notwithstanding the foregoing, if (1) during the last 17 days of the 90-day restricted period, the Company issues an earnings release or material news or a material event relating to the Company occurs; or (2) prior to the expiration of the 90-day restricted period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the 90-day period, the restrictions imposed by this Agreement shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event.

          (j) Use of Proceeds. The Company will apply the net proceeds from the sale of the Securities as described in the Registration Statement, the Time of Sale Information and the Prospectus under the heading “Use of proceeds”.

          (k) No Stabilization. Neither the Company nor any of the Guarantors will take, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in any stabilization or manipulation of the price of the Securities.

          (l) DTC. The Securities shall be eligible for clearance and settlement through DTC.

          (m) Exchange Listing. The Company will use its best efforts to supplementally list the Conversion Shares on the National Association of Securities Dealers Automated Quotations Global Market (the “NASDAQ Global Market”).

          (n) Conversion Shares. The Company will reserve and keep available at all times, free of preemptive rights, the maximum number of Conversion Shares.

          (o) Conversion Price. Between the date hereof and the Closing Date, the Company will not do or authorize any act or thing that would result in an adjustment of the conversion price or conversion rate of the Securities.

          (p) Reports. So long as the Securities are outstanding, the Company will make available to the Representatives, as soon as they are available, copies of all reports or other communications (financial or other) furnished to holders of the Securities, and copies of any reports and financial statements furnished to or filed with the Commission or any national securities exchange or automatic quotation system.

          (q) Record Retention. The Company will, pursuant to reasonable procedures developed in good faith, retain copies of each Issuer Free Writing Prospectus that is not filed with the Commission in accordance with Rule 433 under the Securities Act.

     5. Certain Agreements of the Underwriters. Each Underwriter hereby represents and agrees that:

          (a) It has not and will not use, authorize use of, refer to, or participate in the planning for use of, any “free writing prospectus”, as defined in Rule 405 under the Securities Act (which term includes use of any written information furnished to the Commission by the Company or any Guarantor and not incorporated by reference into the Registration Statement and any press release issued by the Company or any Guarantor) other than (i) a free writing prospectus that contains no “issuer information” (as defined in Rule 433(h)(2) under the Securities Act) that was not included (including through incorporation by reference) in the Preliminary Prospectus or a previously filed Issuer Free Writing Prospectus, (ii) any Issuer Free Writing Prospectus listed on Annex B or prepared pursuant to Section 3(c) or Section 4(c) above, or (iii) any free writing prospectus prepared by such underwriter and approved by the Company in advance in writing (each such free writing prospectus referred to in clauses (i) or (iii), an “Underwriter Free Writing Prospectus”). Notwithstanding the foregoing, the Underwriters may use a term sheet substantially in the form attached as Annex C hereto without the consent of the Company or any Guarantor.

          (b) It has not and will not distribute any Underwriter Free Writing Prospectus referred to in clause (a)(i) in a manner reasonably designed to lead to its broad unrestricted dissemination.

          (c) It has not and will not, without the prior written consent of the Company, use any free writing prospectus that contains the final terms of the Securities unless such terms have previously been included in a free writing prospectus filed with the Commission.

          (d) It will, pursuant to reasonable procedures developed in good faith, retain copies of each free writing prospectus used or referred to by it, in accordance with Rule 433 under the Securities Act.

          (e) It is not subject to any pending proceeding under Section 8A of the Securities Act with respect to the offering (and will promptly notify the Company if any such proceeding against it is initiated during the Prospectus Delivery Period).

     6. Conditions of Underwriters’ Obligations. The obligation of each Underwriter to purchase the Firm Securities on the Closing Date or the Additional Securities on the Additional Closing Date, as the case may be, as provided herein is subject to the performance by the Company and each of the Guarantors of their respective covenants and other obligations hereunder and to the following additional conditions:

          (a) Registration Compliance; No Stop Order. No order suspending the effectiveness of the Registration Statement shall be in effect, and no proceeding for such purpose, pursuant to Rule 401(g)(2) or pursuant to Section 8A under the Securities Act shall be pending before or threatened by the Commission; the Prospectus and each Issuer Free Writing Prospectus shall have been timely filed with the Commission under the Securities Act (in the case of an Issuer Free Writing Prospectus, to the extent required by Rule 433 under the Securities Act) and in accordance with Section 4(a) hereof; and all requests by the Commission for additional information shall have been complied with to the reasonable satisfaction of the Representatives.

          (b) Representations and Warranties. The representations and warranties of the Company and the Guarantors contained herein shall be true and correct on the date hereof and on and as of the Closing Date or the Additional Closing Date, as the case may be; and the statements of the Company, the Guarantors and their respective officers made in any certificates delivered pursuant to this Agreement shall be true and correct on and as of the Closing Date or the Additional Closing Date, as the case may be.

          (c) No Downgrade. Subsequent to the execution and delivery of this Agreement, (i) no downgrading shall have occurred in the rating accorded the Securities or any other debt securities or preferred stock issued or guaranteed by the Company or any of its subsidiaries by any “nationally recognized statistical rating organization”, as such term is defined by the Commission for purposes of Rule 436(g)(2) under the Securities Act and (ii) no such organization shall have publicly announced that it has under surveillance or review, or has changed its outlook with respect to, its rating of the Securities or any other debt securities or preferred stock issued or guaranteed by the Company or any of its subsidiaries (other than an announcement with positive implications of a possible upgrading).

          (d) No Material Adverse Change. No event or condition of a type described in Section 3(g) hereof shall have occurred or shall exist, which event or condition is not described in the Time of Sale Information (excluding any amendment or supplement thereto) and the Prospectus (excluding any amendment or supplement thereto) and the effect of which in the judgment of the Representatives makes it impracticable or inadvisable to proceed with the offering, sale or delivery of the Securities and the Guarantees on the Closing Date or the

Additional Closing Date, as the case may be, on the terms and in the manner contemplated by this Agreement, the Time of Sale Information and the Prospectus.

          (e) Officers’ Certificates. The Representatives shall have received on and as of the Closing Date or the Additional Closing Date, as the case may be, a certificate of the Company’s chief financial officer or chief accounting officer of the Company and one additional senior executive officer of the Company who is satisfactory to the Representatives and a certificate of two executive officers of each Guarantor who have specific knowledge of such Guarantor’s financial matters and are satisfactory to the Representatives (i) confirming that such officers have carefully reviewed the Registration Statement, the Time of Sale Information and the Prospectus and, to the knowledge of such officers, the representations set forth in Sections 3(b) and 3(d) hereof are true and correct, (ii) confirming that the other representations and warranties of the Company and each of the Guarantors, as applicable, in this Agreement are true and correct and that the Company and each of the Guarantors, as applicable, have complied with all agreements and satisfied all conditions on their part to be performed or satisfied hereunder at or prior to such Closing Date, (iii) confirming that the Company and its subsidiaries are in compliance with the financial covenants and other covenants of the Credit Agreement, the DHS Credit Agreement, and the 2005 Indenture and (iv) to the effect set forth in paragraphs (a), (c) and (d) above.

          (f) Comfort Letters. On the date of this Agreement and on the Closing Date or the Additional Closing Date, as the case may be, KPMG LLC shall have furnished to the Representatives, at the request of the Company, letters, dated the respective dates of delivery thereof and addressed to the Underwriters, in form and substance reasonably satisfactory to the Representatives, containing statements and information of the type customarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus; provided, that the letter delivered on the Closing Date or the Additional Closing Date, as the case may be, shall use a “cut-off” date no more than three business days prior to such Closing Date or such Additional Closing Date, as the case may be.

          (g) Reserve Report Confirmation Letters. On the date of this Agreement and on the Closing Date or the Additional Closing Date, as the case may be, each of Ralph E. Davis Associates, Inc. and Mannon Associates, Inc. shall have furnished to the Representative, at the request of the Company, reserve report confirmation letters, dated the respective dates of delivery thereof and addressed to the Underwriters, in form and substance reasonably satisfactory to the Representatives, containing statements and information of the type customarily included in such letters to underwriters with respect to the oil and gas reserve and other operational information of the Company and its subsidiaries contained in the Registration Statement, the Time of Sale Information and the Prospectus.

          (h) Opinion of Counsel for the Company and the Guarantors. Davis Graham & Stubbs LLP, counsel for the Company and the Guarantors, shall have furnished to the Representatives, at the request of the Company, their written opinion, dated the Closing Date or the Additional Closing Date, as the case may be, and addressed to the Underwriters, in form and

substance reasonably satisfactory to the Representatives, substantially to the effect set forth in Annex D hereto.

          (i) Opinion of General Counsel. Stanley F. Freedman, Executive Vice President, General Counsel and Secretary of the Company, shall have furnished to the Representatives, at the request of the Company, his written opinion, dated the Closing Date or the Additional Closing Date, as the case may be, and addressed to the Underwriters, in form and substance reasonably satisfactory to the Representatives, substantially to the effect set forth in Annex E hereto.

          (j) Opinion of Counsel for the Underwriters. The Representatives shall have received on and as of the Closing Date or the Additional Closing Date, as the case may be, an opinion of Simpson Thacher & Bartlett LLP, counsel for the Underwriters, with respect to such matters as the Representatives may reasonably request, and such counsel shall have received such documents and information as they may reasonably request to enable them to pass upon such matters.

          (k) No Legal Impediment to Issuance. No action shall have been taken and no statute, rule, regulation or order shall have been enacted, adopted or issued by any federal, state or foreign governmental or regulatory authority that would, as of the Closing Date or the Additional Closing Date, as the case may be, prevent the issuance or sale of the Securities or the issuance or sale of the Guarantees or the issuance of the Conversion Shares; and no injunction or order of any federal, state or foreign court shall have been issued that would, as of the Closing Date or the Additional Closing Date, as the case may be, prevent the issuance or sale of the Securities or the issuance or sale of the Guarantees or the issuance of the Conversion Shares.

          (l) Good Standing. The Representatives shall have received on and as of the Closing Date or the Additional Closing Date, as the case may be, satisfactory evidence of the good standing of the Company and its subsidiaries in their respective jurisdictions of organization and their good standing as foreign entities in such other jurisdictions as the Representatives may reasonably request, in each case in writing or any standard form of telecommunication from the appropriate governmental authorities of such jurisdictions.

          (m) Indenture and Securities. The Indenture shall have been duly executed and delivered by the Company, each of the Guarantors and the Trustee, and the Securities shall have been duly executed and delivered by the Company and duly authenticated by the Trustee.

          (n) DTC. The Securities shall be eligible for clearance and settlement through DTC.

          (o) Exchange Listing. The Company shall have used its best efforts to have the Conversion Shares approved for supplemental listing, subject to official notice of issuance, on the NASDAQ Global Market.

          (p) Lock-up Agreements. The “lock-up” agreements, each substantially in the form of Exhibit A hereto, from all executive officers and directors of the Company relating to sales and certain other dispositions of shares of Common Stock or certain other securities,

delivered to the Underwriters on or before the date hereof, shall be full force and effect on the Closing Date or the Additional Closing Date, as the case may be.

          (q) Additional Documents. On or prior to the Closing Date or the Additional Closing Date, as the case may be, the Company shall have furnished to the Representatives such further certificates and documents as the Representatives may reasonably request.

     All opinions, letters, certificates and evidence mentioned above or elsewhere in this Agreement shall be deemed to be in compliance with the provisions hereof only if they are in form and substance reasonably satisfactory to counsel for the Underwriters.

     7. Indemnification and Contribution.

          (a) Indemnification of the Underwriters. The Company and each of the Guarantors jointly and severally agree to indemnify and hold harmless each Underwriter, its affiliates, directors and officers and each person, if any, who controls such Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act, from and against any and all losses, claims, damages and liabilities (including, without limitation, legal fees and other reasonable expenses incurred in connection with any suit, action or proceeding or any claim asserted, as such fees and expenses are incurred), joint or several, that arise out of, or are based upon, (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary in order to make the statements therein, not misleading, or (ii) any untrue statement or alleged untrue statement of a material fact contained in the Prospectus (or any amendment or supplement thereto), any Issuer Free Writing Prospectus or any Time of Sale Information (including any Time of Sale Information that has subsequently been amended), or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading, in each case except insofar as such losses, claims, damages or liabilities arise out of, or are based upon, any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with any information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the information described as such in subsection (b) below.

          (b) Indemnification of the Company and the Guarantors. Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, each of the Guarantors, each of their respective directors and each of their respective officers who signed the Registration Statement and each person, if any, who controls the Company or any of the Guarantors within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act to the same extent as the indemnity set forth in paragraph (a) above, but only with respect to any losses, claims, damages or liabilities that arise out of, or are based upon, any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with any information relating to such Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in the Registration Statement, the Prospectus (or any amendment or supplement thereto), any Issuer Free Writing

Prospectus or any Time of Sale Information, it being understood and agreed upon that the only such information furnished by any Underwriter consists of the following information in the Prospectus furnished on behalf of each Underwriter: the concession and reallowance figures appearing in the fourth paragraph under the caption “Underwriting” and the information regarding stabilization transactions contained in the fifteenth and sixteenth paragraphs under the caption “Underwriting.”

          (c) Notice and Procedures. If any suit, action, proceeding (including any governmental or regulatory investigation), claim or demand shall be brought or asserted against any person in respect of which indemnification may be sought pursuant to either paragraph (a) or (b) above, such person (the “Indemnified Person”) shall promptly notify the person against whom such indemnification may be sought (the “Indemnifying Person”) in writing; provided that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have under this Section 7 except to the extent that it has been materially prejudiced (through the forfeiture of substantive rights or defenses) by such failure; and provided, further, that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have to an Indemnified Person otherwise than under this Section 7. If any such proceeding shall be brought or asserted against an Indemnified Person and it shall have notified the Indemnifying Person thereof, the Indemnifying Person shall retain counsel reasonably satisfactory to the Indemnified Person (who shall not, without the consent of the Indemnified Person, be counsel to the Indemnifying Person) to represent the Indemnified Person in such proceeding and shall pay the reasonable fees and expenses of such counsel related to such proceeding, as incurred. In any such proceeding, any Indemnified Person shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such Indemnified Person unless (i) the Indemnifying Person and the Indemnified Person shall have mutually agreed to the contrary or (ii) the Indemnifying Person has failed within a reasonable time to retain counsel reasonably satisfactory to the Indemnified Person. It is understood and agreed that the Indemnifying Person shall not, in connection with any proceeding or related proceeding in the same jurisdiction, be liable for the fees and expenses of more than one separate firm (in addition to any local counsel) for all Indemnified Persons, and that all such reimbursable fees and expenses shall be paid or reimbursed as they are incurred. Any such separate firm for any Underwriter, its affiliates, directors and officers and any control persons of such Underwriter shall be designated in writing by the Representatives and any such separate firm for the Company, the Guarantors, their respective directors and their respective officers who signed the Registration Statement and any control persons of the Company and the Guarantors shall be designated in writing by the Company. The Indemnifying Person shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the Indemnifying Person agrees to indemnify each Indemnified Person from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an Indemnified Person shall have requested that an Indemnifying Person reimburse the Indemnified Person for fees and expenses of counsel as contemplated by this paragraph, the Indemnifying Person shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 45 days after receipt by the Indemnifying Person of the proposed terms of the settlement and (ii) the Indemnifying Person shall not have reimbursed the Indemnified Person in accordance with such request prior to the date of such settlement. No Indemnifying Person shall, without the written consent of the Indemnified Person, effect any settlement of any pending or threatened

proceeding in respect of which any Indemnified Person is or would reasonably have been expected to have been a party and indemnification could have been sought hereunder by such Indemnified Person, unless such settlement (x) includes an unconditional release of such Indemnified Person, in form and substance reasonably satisfactory to such Indemnified Person, from all liability on claims that are the subject matter of such proceeding and (y) does not include any statement as to or any admission of fault, culpability or a failure to act by or on behalf of any Indemnified Person.

          (d) Contribution. If the indemnification provided for in paragraphs (a) and (b) above is unavailable to an Indemnified Person or insufficient in respect of any losses, claims, damages or liabilities referred to therein, then each Indemnifying Person under such paragraph, in lieu of indemnifying such Indemnified Person thereunder, shall contribute to the amount paid or payable by such Indemnified Person as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the relative benefits received by the Company and the Guarantors, on the one hand, and the Underwriters, on the other, from the offering of the Securities or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) but also the relative fault of the Company and the Guarantors , on the one hand, and the Underwriters, on the other, in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, as well as any other relevant equitable considerations. The relative benefits received by the Company and the Guarantors, on the one hand, and the Underwriters, on the other, shall be deemed to be in the same respective proportions as the net proceeds (before deducting expenses) received by the Company from the sale of the Securities and the total underwriting discounts and commissions received by the Underwriters in connection therewith, in each case as set forth in the table on the cover of the Prospectus, bear to the aggregate offering price of the Securities. The relative fault of the Company and the Guarantors, on the one hand, and the Underwriters, on the other, shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company or any Guarantor or by the Underwriters, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

          (e) Limitation on Liability. The Company, the Guarantors and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 7 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take account of the equitable considerations referred to in paragraph (d) above. The amount paid or payable by an Indemnified Person as a result of the losses, claims, damages and liabilities referred to in paragraph (d) above shall be deemed to include, subject to the limitations set forth above, any legal or other expenses incurred by such Indemnified Person in connection with any such action or claim. Notwithstanding the provisions of this Section 7, in no event shall an Underwriter be required to contribute any amount in excess of the amount by which the total underwriting discounts and commissions received by such Underwriter with respect to the offering of the Securities exceeds the amount of any damages that such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f)

of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute pursuant to this Section 7 are several in proportion to their respective purchase obligations hereunder and not joint.

          (f) Non-Exclusive Remedies. The remedies provided for in this Section 7 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any Indemnified Person at law or in equity.

     8. Effectiveness of Agreement. This Agreement shall become effective upon the execution and delivery hereof by the parties hereto.

     9. Termination. This Agreement may be terminated in the absolute discretion of the Representatives, by notice to the Company, if after the execution and delivery of this Agreement and prior to the Closing Date or, in the case of the Additional Securities, prior to the Additional Closing Date (i) trading generally shall have been suspended or materially limited on or by any of the New York Stock Exchange, the American Stock Exchange, the National Association of Securities Dealers, Inc., the Chicago Board Options Exchange, the Chicago Mercantile Exchange or the Chicago Board of Trade; (ii) trading of any securities issued or guaranteed by the Company or any of the Guarantors shall have been suspended on any exchange or in any over-the-counter market; (iii) a general moratorium on commercial banking activities shall have been declared by federal or New York State authorities; or (iv) there shall have occurred any outbreak or escalation of hostilities or any change in financial markets or any calamity or crisis, either within or outside the United States, that, in the judgment of the Representatives, is material and adverse and makes it impracticable or inadvisable to proceed with the offering, sale or delivery of the Securities on the Closing Date or the Additional Closing Date, as the case may be, on the terms and in the manner contemplated by this Agreement, the Time of Sale Information and the Prospectus.

     10. Defaulting Underwriter. If, on the Closing Date or the Additional Closing Date, as the case may be, any Underwriter defaults on its obligation to purchase the Securities that it has agreed to purchase hereunder on such date, the non-defaulting Underwriters may in their discretion arrange for the purchase of such Securities by other persons satisfactory to the Company on the terms contained in this Agreement. If, within 36 hours after any such default by any Underwriter, the non-defaulting Underwriters do not arrange for the purchase of such Securities, then the Company shall be entitled to a further period of 36 hours within which to procure other persons satisfactory to the non-defaulting Underwriters to purchase such Securities on such terms. If other persons become obligated or agree to purchase the Securities of a defaulting Underwriter, either the non-defaulting Underwriters or the Company may postpone the Closing Date or the Additional Closing Date, as the case may be, for up to five full business days in order to effect any changes that in the opinion of counsel for the Company or counsel for the Underwriters may be necessary in the Registration Statement and the Prospectus or in any other document or arrangement, and the Company and the Guarantors agree to promptly prepare any amendment or supplement to the Registration Statement and the Prospectus that effects any such changes. As used in this Agreement, the term “Underwriter” includes, for all purposes of this Agreement unless the context otherwise requires, any person not listed in Schedule 1 hereto that, pursuant to this Section 10, purchases Securities that a defaulting Underwriter agreed but failed to purchase.

          (a) If, after giving effect to any arrangements for the purchase of the Securities of a defaulting Underwriter or Underwriters by the non-defaulting Underwriters and the Company as provided in paragraph (a) above, the aggregate principal amount of Securities that remain unpurchased on the Closing Date or the Additional Closing Date, as the case may be, does not exceed one-eleventh of the aggregate principal amount of Securities to be purchased on such date, then the Company shall have the right to require each non-defaulting Underwriter to purchase the principal amount of Securities

that such Underwriter agreed to purchase hereunder on such date plus such Underwriter’s pro rata share (based on the principal amount of Securities that such Underwriter agreed to purchase on such date) of the Securities of such defaulting Underwriter or Underwriters for which such arrangements have not been made.

          (b) If, after giving effect to any arrangements for the purchase of the Securities of a defaulting Underwriter or Underwriters by the non-defaulting Underwriters and the Company as provided in paragraph (a) above, the aggregate principal amount of Securities that remain unpurchased on the Closing Date or the Additional Closing Date, as the case may be, exceeds one-eleventh of the aggregate amount of Securities to be purchased on such date, or if the Company shall not exercise the right described in paragraph (b) above, then this Agreement or, with respect to any Additional Closing Date, the obligation of the Underwriters to purchase Securities on the Additional Closing Date, as the case may be, shall terminate without liability on the part of the non-defaulting Underwriters. Any termination of this Agreement pursuant to this Section 10 shall be without liability on the part of the Company or the Guarantors, except that the Company and each of the Guarantors will continue to be liable for the payment of expenses as set forth in Section 11 hereof and except that the provisions of Section 7 hereof shall not terminate and shall remain in effect.

          (c) Nothing contained herein shall relieve a defaulting Underwriter of any liability it may have to the Company, any Guarantor or any non-defaulting Underwriter for damages caused by its default.

     11. Payment of Expenses. Whether or not the transactions contemplated by this Agreement are consummated or this Agreement is terminated, the Company and each of the Guarantors jointly and severally agree to pay or cause to be paid all costs and expenses incident to the performance of their respective obligations hereunder, including without limitation, (i) the costs incident to the authorization, issuance, sale, preparation and delivery of the Securities, the Guarantees or the Conversion Shares and any taxes payable in that connection; (ii) the costs incident to the preparation, printing and filing under the Securities Act of the Registration Statement, the Preliminary Prospectus, any Issuer Free Writing Prospectus, any Time of Sale Information and the Prospectus (including all exhibits, amendments and supplements thereto) and the distribution thereof; (iii) the costs of reproducing and distributing each of the Transaction Documents; (iv) the fees and expenses of the Company’s and the Guarantors’ counsel and independent accountants; (v) the fees and expenses incurred in connection with the registration or qualification and determination of eligibility for investment of the Securities, the Guarantees or the Conversion Shares under the laws of such jurisdictions as the Representatives may designate and the preparation, printing and distribution of a Blue Sky Memorandum (including the related fees and expenses of counsel for the Underwriters); (vi) any fees charged by rating agencies for rating the Securities; (vii) the fees and expenses of the Trustee and any paying agent (including related fees and expenses of any counsel to such parties); (viii) the cost of preparing stock certificates; (ix) the costs and charges of any transfer agent and any registrar; (x) all expenses and application fees incurred in connection with any filing with, and clearance of the offering by, the National Association of Securities Dealers, Inc.; (xi) all expenses incurred by the Company in connection with any “road show” presentation to potential investors; (xii) all expenses and application fees related to the approval of the Securities for book-entry transfer by DTC; and (xiii) all expenses and application fees related to the listing of the Conversion Shares on the NASDAQ Global Market.

          (a) If (i) this Agreement is terminated pursuant to Section 9, (ii) the Company for any reason fails to tender the Securities for delivery to the Underwriters or (iii) the Underwriters decline to purchase the Securities for any reason permitted under this Agreement, the Company and each of the Guarantors jointly and severally agree to reimburse the Underwriters for all out-of-pocket costs and expenses (including the fees and expenses of their counsel) reasonably incurred by the Underwriters in connection with this Agreement and the offering contemplated hereby.

     12. Persons Entitled to Benefit of Agreement. This Agreement shall inure to the benefit of and be binding upon the parties hereto and their respective successors and the officers and directors and any controlling persons referred to in Section 7 hereof. Nothing in this Agreement is intended or shall be construed to give any other person any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision contained herein. No purchaser of Securities from any Underwriter shall be deemed to be a successor merely by reason of such purchase.

     13. Survival. The respective indemnities, rights of contribution, representations, warranties and agreements of the Company, each of the Guarantors and the Underwriters contained in this Agreement or made by or on behalf of the Company, each of the Guarantors or the Underwriters pursuant to this Agreement or any certificate delivered pursuant hereto shall survive the delivery of and payment for the Securities and shall remain in full force and effect, regardless of

any termination of this Agreement or any investigation made by or on behalf of the Company, the Guarantors or the Underwriters.

     14. Certain Defined Terms. For purposes of this Agreement, (a) except where otherwise expressly provided, the term “affiliate” has the meaning set forth in Rule 405 under the Securities Act; (b) the term “business day” means any day other than a day on which banks are permitted or required to be closed in New York City; and (c) the term “subsidiary” has the meaning set forth in Rule 405 under the Securities Act.

     15. Miscellaneous. (a) Authority of the Representatives. Any action by the Underwriters hereunder may be taken by the Representatives on behalf of the Underwriters, and any such action taken by the Representatives shall be binding upon the Underwriters.

          (b) Notices. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted and confirmed by any standard form of telecommunication. Notices to the Underwriters shall be given to the Representatives c/o J.P. Morgan Securities Inc., 277 Park Avenue, New York, New York 10172 (fax: (212)  ###-###-####), Attention: Equity Syndicate Desk; c/o Lehman Brothers Inc., 745 Seventh Avenue, New York, New York 10019 (fax: (646)  ###-###-####), Attention: Syndicate Department; and c/o Deutsche Bank Securities Inc., 60 Wall Street, New York, New York 10005 (fax: (212)  ###-###-####); Attention: Syndicate Manager (with a copy to the General Counsel (fax: (212)  ###-###-####)). Notices to the Company shall be given to it at 370 17th Street, Suite 4300, Denver, Colorado 80202, (fax: (303) 293-0066); Attention: Executive Vice President, General Counsel and Secretary.

          (c) Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the State of New York.

          (d) Counterparts. This Agreement may be signed in counterparts (which may include counterparts delivered by any standard form of telecommunication), each of which shall be an original and all of which together shall constitute one and the same instrument.

          (e) Amendments or Waivers. No amendment or waiver of any provision of this Agreement, nor any consent or approval to any departure therefrom, shall in any event be effective unless the same shall be in writing and signed by the parties hereto.

          (f) Headings. The headings herein are included for convenience of reference only and are not intended to be part of, or to affect the meaning or interpretation of, this Agreement.

     If the foregoing is in accordance with your understanding, please indicate your acceptance of this Agreement by signing in the space provided below.

		Very truly yours,
		DELTA PETROLEUM CORPORATION
		By		/s/ Stanley F. Freedman
				Title: Executive VP
		PIPER PETROLEUM COMPANY
		By		/s/ Stanley F. Freedman
				Title: Executive VP
		DELTA EXPLORATION COMPANY, INC.
		By		/s/ Stanley F. Freedman
				Title: Executive VP
		CASTLE TEXAS EXPLORATION LIMITED PARTNERSHIP
		By		/s/ Stanley F. Freedman
				Title: Executive VP of Delta Petroleum Corporation, the sole General Partner and sole Limited Partner
		DPCA, LLC
		By		/s/ Stanley F. Freedman
				Title: Executive VP of Delta Petroleum Corporation, the sole member and manager
		DLC, INC.
		By		/s/ Stanley F. Freedman
				Title: Executive VP

Accepted: April 19, 2007

For themselves and on behalf of the
several Underwriters listed in
Schedule 1 hereto.

J.P. MORGAN SECURITIES INC.
By		/s/ Paul Ohern
		Authorized Signatory
LEHMAN BROTHERS INC.
By		/s/ Arlene Salmonson
		Authorized Signatory
DEUTSCHE BANK SECURITIES INC.
By		/s/ James C.V. Rogers
		Authorized Signatory
By		/s/ Jon R. Marinelli
		Authorized Signatory

Schedule 1

Underwriter		Principal Amount
J.P. Morgan Securities Inc.		$	37,500,000
Lehman Brothers Inc.			27,500,000
Deutsche Bank Securities Inc.			15,000,000
Raymond James & Associates, Inc.			7,000,000
Coker, Palmer, Phillips & Mullen, Inc.			5,000,000
KeyBanc Capital Markets Inc.			5,000,000
Tristone Capital (U.S.A.) Inc.			3,000,000
Total		$	100,000,000

Schedule 2

Subsidiary Guarantors

Name		State of Incorporation
Piper Petroleum Company		Colorado
Delta Exploration Company, Inc.		Colorado
Castle Texas Exploration Limited Partnership		Texas
DPCA, LLC		Delaware
DLC, Inc.		Colorado

Annex A

Owned or Controlled Entities

		State of
Subsidiaries		Incorporation		% Ownership
Amber Resources Company of Colorado		Delaware		91.68%
Piper Petroleum Company		Colorado		100%
Delta Exploration Company, Inc.		Colorado		100%
Castle Texas Exploration Limited Partnership (1)		Texas		100%
DPCA, LLC (1)		Delaware		100%
DLC, Inc.		Colorado		100%
DHS Holding Company		Delaware		49.4%
DHS Drilling Company		Colorado		49.4%
C&L Drilling Company		Colorado		49.4%
Chapman Trucking Company		Wyoming		49.4%
PGR Partners, LLC (1)		Colorado		74.37%
CRB Partners, LLC (1)		Delaware		56.23%
Polymath Partners, LLC (1)		Colorado		70.00%

Exhibit A

FORM OF LOCK-UP AGREEMENT

                     ___, 2007

J.P. MORGAN SECURITIES INC.
LEHMAN BROTHERS INC.
DEUTSCHE BANK SECURITIES INC.
As Representatives of
the several Underwriters listed in
Schedule I to the Underwriting
Agreement referred to below
c/o J.P. Morgan Securities Inc.
277 Park Avenue
New York, NY 10172

     Re: Delta Petroleum Corporation – Public Offering

Ladies and Gentlemen:

     The undersigned understands that you, as Representatives of the several Underwriters, propose to enter into an Underwriting Agreement (the “Underwriting Agreement”) with Delta Petroleum Corporation, a Delaware corporation (the “Company”) and the subsidiaries of the Company listed in Annex A to the Underwriting Agreement, providing for the public offering (the “Public Offering”) by the several Underwriters named in Schedule I to the Underwriting Agreement (the “Underwriters”), of the Company’s Convertible Senior Notes due 2037 (the “Securities”). Capitalized terms used herein and not otherwise defined shall have the meanings set forth in the Underwriting Agreement.

     In consideration of the Underwriters’ agreement to purchase and make the Public Offering of the Securities, and for other good and valuable consideration receipt of which is hereby acknowledged, the undersigned hereby agrees that, without the prior written consent of J.P. Morgan Securities Inc., the undersigned will not, during the period ending 90 days after the date of the final prospectus relating to the Public Offering (the “Prospectus”), (1) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock, $0.01 per share par value, of the Company (the “Common Stock”) or any securities convertible into or exercisable or exchangeable for Common Stock (including without limitation, Common Stock which may be deemed to be beneficially owned by the undersigned in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) and securities which may be issued upon exercise of a stock option or warrant) or (2) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise. In addition, the undersigned agrees that, without the prior written consent of J.P. Morgan Securities Inc., it

will not, during the period ending 90 days after the date of the Prospectus, make any demand for or exercise any right with respect to, the registration of any shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock. Notwithstanding the foregoing, if (1) during the last 17 days of the 90-day restricted period, the Company issues an earnings release or material news or a material event relating to the Company occurs; or (2) prior to the expiration of the 90-day restricted period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the 90-day period, the restrictions imposed by this Letter Agreement shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event (such 90-day restricted period, so extended, the “Lock-Up Period”).

     The restrictions described in the immediately preceding paragraph shall not apply to:

	(i)		transfers by the undersigned of Common Stock as a bona fide gift or transfer by will or the laws of intestate succession, so long as (1) each transferee agrees in writing to be subject to the restrictions set forth herein, (2) the Underwriters have been advised in writing at least two business days prior to the proposed transfer and (3) no filing by any party with the SEC or any other public disclosure shall be required or voluntarily made in connection with such transfer during the Lock-Up Period; or
	(ii)		transfers by the undersigned of Common Stock to any trust, partnership or limited liability company for the direct or indirect benefit of such person for estate planning purposes, so long as (1) the trustee, partnership or limited liability company agrees in writing to be subject to the restrictions set forth herein, (2) any such transfer shall not involve a disposition for value and (3) no filing by any party with the SEC or any other public disclosure shall be required or voluntarily made in connection with such transfer during the Lock-Up Period.

     In furtherance of the foregoing, the Company, and any duly appointed transfer agent for the registration or transfer of the securities described herein, are hereby authorized to decline to make any transfer of securities if such transfer would constitute a violation or breach of this Letter Agreement.

     The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this Letter Agreement. All authority herein conferred or agreed to be conferred and any obligations of the undersigned shall be binding upon the successors, assigns, heirs or personal representatives of the undersigned.

     The undersigned understands that, if the Underwriting Agreement does not become effective, or if the Underwriting Agreement (other than the provisions thereof which survive termination) shall terminate or be terminated prior to payment for and delivery of the Common Stock to be sold thereunder, the undersigned shall be released from all obligations under this Letter Agreement. The undersigned understands that the Underwriters are entering into the Underwriting Agreement and proceeding with the Public Offering in reliance upon this Letter Agreement.

     This Letter Agreement shall be governed by and construed in accordance with the laws of the State of New York, without regard to the conflict of laws principles thereof.

		Very truly yours,
		(signature)
		(print name)