Exhibit 25.1

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Form T-1

STATEMENT OF ELIGIBILITY
UNDER THE TRUST INDENTURE ACT OF 1939 OF A
CORPORATION DESIGNATED TO ACT AS TRUSTEE

o

CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2)

WELLS FARGO BANK, NATIONAL ASSOCIATION
(Exact name of trustee as specified in its charter)

Wells Fargo & Company
Law Department, Trust Section
MAC N9305-175
Sixth Street and Marquette Avenue, 17^th Floor
Minneapolis, Minnesota 55479
(612) 667-4608
(Name, address and telephone number of agent for service)

ST. MARY LAND & EXPLORATION COMPANY
(Exact name of obligor as specified in its charter)

3.50% Senior Convertible Notes due 2027
(Title of indenture securities)

TABLE OF CONTENTS

Item 1. General Information. Furnish the following information as to the trustee:

(a.)

Name and address of each examining or supervising authority to which it is subject.

Comptroller of the Currency
Treasury Department
Washington, D.C.

Federal Deposit Insurance Corporation
Washington, D.C.

Federal Reserve Bank of San Francisco
San Francisco, California 94120

(b.)

Whether it is authorized to exercise corporate trust powers.

The trustee is authorized to exercise corporate trust powers.

Item 2. Affiliations with Obligor. If the obligor is an affiliate of the trustee, describe each such affiliation.

        None with respect to the trustee.

        No responses are included for Items 3-14 of this form T-1 because the obligor is not in default as provided under Item 13.

Item 15. Foreign Trustee. Not applicable.

Item 16. List of Exhibits. List below all exhibits filed as a part of this Statement of Eligibility.

*

Incorporated by reference to the exhibit of the same number to the trustee's Form T-1 filed as exhibit 25 to the Form S-4 dated December 30, 2005 of Hornbeck Offshore Services LLC file number 333-130784-06.

**

Incorporated by reference to the exhibit of the same number to the trustee's Form T-1 filed as exhibit 25 to the Form T-3 dated March 3, 2004 of Trans-Lux Corporation file number 022-28721.

***

Incorporated by reference to the exhibit of the same number to the trustee's Form T-1 filed as exhibit 25 to the Form S-4 dated May 26, 2005 of Penn National Gaming Inc. file number 333-125274.

SIGNATURE

        Pursuant to the requirements of the Trust Indenture Act of 1939, as amended, the trustee, Wells Fargo Bank, National Association, a national banking association organized and existing under the laws of the United States of America, has duly caused this statement of eligibility to be signed on its behalf by the undersigned, thereunto duly authorized, all in the City of Denver and State of Colorado, on the 15^th day of June, 2007.

EXHIBIT 6

June 15, 2007

Securities and Exchange Commission
Washington, D.C. 20549

Gentlemen:

        In accordance with Section 321(b) of the Trust Indenture Act of 1939, as amended, the undersigned hereby consents that reports of examination of the undersigned made by Federal, State, Territorial or District authorities authorized to make such examinations may be furnished by such authorities to the Securities and Exchange Commission upon its request therefor.

Exhibit 7
Consolidated Report of Condition of
Wells Fargo Bank National Association
of 101 North Phillips Avenue, Sioux Falls, SD 57104
And Foreign and Domestic Subsidiaries,
at the close of business March 31, 2007, filed in accordance with 12 U.S.C. §161 for National Banks.

        I, Howard I. Atkins, EVP & CFO of the above-named bank do hereby declare that this Report of Condition has been prepared in conformance with the instructions issued by the appropriate Federal regulatory authority and is true to the best of my knowledge and belief.

        We, the undersigned directors, attest to the correctness of this Report of Condition and declare that it has been examined by us and to the best of our knowledge and belief has been prepared in conformance with the instructions issued by the appropriate Federal regulatory authority and is true and correct.

QuickLinks

Exhibit 25.1