EXHIBIT 23.3
CONSENT OF INDEPENDENT
PETROLEUM ENGINEERS AND GEOLOGISTS
The
undersigned hereby consents to the references to our firm in the form and
context in which they appear in the Annual Report on Form 10-K/A of St. Mary
Land & Exploration Company for the year ended December 31,
2007. We hereby further consent to the use of information contained
in our reports, as of December 31, 2007 setting forth the estimates of revenues
from St. Mary Land & Exploration Company's oil and gas
reserves. We further consent to the incorporation by reference
thereof into St. Mary Land & Exploration Company's Post-Effective Amendment
No. 1 to Registration Statement Nos. 333-30055, 333-35352, 333-88780, and
333-106438 on Form S-8 and Registration Statement Nos. 033-61850, 333-58273, and
333-134221 on Form S-8, and Registration Statement Nos. 333-88712 and 333-143815
on Form S-3.
NETHERLAND, SEWELL
& ASSOCIATES, INC.
By: /s/ C.H. (SCOTT) REES
III
C.H. (Scott) Rees III,
P.E.
Chairman and Chief Executive
Officer
Dallas,
Texas
March 4,
2008