FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * BEST ANTHONY JAMES   2. Issuer Name and Ticker or Trading Symbol ST MARY LAND & EXPLORATION CO [SM] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CEO & President (Last) (First) (Middle) 1775 SHERMAN STREET, SUITE 1200 3. Date of Earliest Transaction (Month/Day/Year) 02/28/2010 (Street) DENVER, CO 80203 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock; $.01 Par Value 02/28/2010   M   432 A (1) 44,354 D   Common Stock; $.01 Par Value 02/28/2010   M   1,131 A (2) 45,485 D   Common Stock; $.01 Par Value 02/28/2010   A(3)   1,250 A (3) 46,735 D

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Restricted Stock Units

(1)

02/28/2010

M

432

02/28/2010

02/28/2010

Common Stock

432

$ 0

0

D

Restricted Stock Units

(2)

02/28/2010

M

1,131

02/28/2010

02/28/2010

Common Stock

1,131

$ 0

1,131

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
BEST ANTHONY JAMES 1775 SHERMAN STREET SUITE 1200 DENVER, CO 80203	X		CEO & President

Signatures

Karin M. Writer (Attorney-In-Fact)		03/02/2010
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Each restricted stock unit represents a contingent right to receive one share of stock. The restricted stock units were granted on February 28, 2007, are associated with fiscal year 2006, and vest in four equal installments beginning on the grant date. On the vesting dates, shares are issued to the reporting person, at which time all restrictions on the vested shares will lapse.
(2)	Each restricted stock unit represents a contingent right to receive one share of stock. The restricted stock units were granted on February 28, 2008, are associated with fiscal year 2007, and vest in four equal installments beginning on the grant date. On the vesting dates, shares are issued to the reporting person, at which time all restrictions on the vested shares will lapse.
(3)	Mr. Best acquired 1,250 shares of the issuer's common stock on February 28, 2010. Mr. Best may earn an additional 1,250 shares in each of the first quarters of 2008, 2009, and 2010 if he is employed by the issuer at the time. He may also earn an additional 2,500 to 3,750 shares with each of these additional share grants if certain net asset value growth percentages are met.

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