Exhibit 99.1



                                                             For Information
                                                             Mark A. Hellerstein
                                                             Robert T. Hanley
                                                             303-861-8140


FOR IMMEDIATE RELEASE

         ST. MARY ANNOUNCES ACQUISITION, PROVIDES OPERATIONS UPDATE AND
           SCHEDULES SECOND QUARTER 2005 EARNINGS CONFERENCE CALL FOR
                                 AUGUST 4, 2005

DENVER, June 29, 2005 - St. Mary Land & Exploration Company (NYSE: SM) today
announced that it has signed an agreement to acquire oil and gas properties,
provided an update of its operations and updated its guidance for the second
quarter and full year 2005. In addition, St. Mary has scheduled its second
quarter 2005 earnings conference call for August 4, 2005.

The Company announced that through its wholly owned subsidiary Nance Petroleum
Corporation, it has agreed to acquire oil and gas properties with an estimated
18.7 BCFE of proved risked reserves, 94% developed, for $39 million in cash with
an effective date of May 1, 2005. The properties to be acquired are located
primarily in the Wind River and Powder River Basins of Wyoming and currently
produce an estimated 530 barrels of oil and 3,200 Mcf of gas per day, or 6,400
MCFE per day. In addition, the acquisition will include approximately 7,200 net
acres of undeveloped oil and gas leases. Approximately 100% of the estimated oil
and gas production over the next two years is hedged at average NYMEX prices of
$56.70 per barrel of oil and $7.45 per MMBtu of natural gas. The acquisition is
expected to close August 2, 2005 upon completion of customary due diligence. The
cash to be delivered at closing will reflect customary adjustments for net
revenues between the effective and closing dates. Payment for the properties
will be made from cash on hand and funds available under St. Mary's existing
credit facility.

             SECOND QUARTER 2005 EXPLORATION AND DEVELOPMENT PROGRAM

ROCKIES REGION

Year to date, St. Mary has participated in 22 successful completions, with no
dry holes, in the Bakken play in the Williston Basin. Two Bakken wells are
currently being completed and six wells are drilling in the play. Bakken wells
completed during the second quarter include the Charlie Creek 2-33H (SM 61% WI)
completed at a rate of 620 BOEPD, the Norgaard 12-6H (SM 83% WI) completed at an
initial ten day average rate of 510 BOEPD and the Stone Bonnie 1-5H (SM 50% WI)





completed at an initial eight day average rate of 760 BOEPD. On its North Dakota
acreage, the Company has reentered seven wellbores and in each of the wellbores
has drilled single laterals to test the Bakken. Results have been mixed with an
average initial post frac production rate of 125 BOEPD from the six wells
completed to date. One well is currently drilling in North Dakota. New
completion techniques, such as multi-lateral completions, are being considered
to improve well production and economics.

Since inception of the project the Company has completed 79 wells in its Hanging
Woman Basin coalbed natural gas program in the northern Powder River Basin
producing 1,920 MCFD, of which 1,680 MCFD, net of compressor usage, is being
sold. Current production rates have exceeded the Company's expectations at this
stage of the program. An additional 26 wells have been drilled and are expected
to go on production by August 1 when the infrastructure for the wells is
complete. Permitting and construction of infrastructure for 98 wells is in
progress. It is anticipated that these wells will be drilled before year-end,
which will result in 147 total wells being drilled in 2005.

MID-CONTINENT REGION

In Northeast Mayfield, the Company currently has two operated rigs drilling in
the field. Completed wells in Northeast Mayfield during the second quarter
include the RDB 6-36 (SM 31% WI) completed at a rate of 7,200 MCFED and the Kula
Rae 1-33 (SM 31% WI) completed at a rate of 4,300 MCFED.

In Centrahoma, the Company has reached total depth and is running casing on the
Ann Bey 2-7 (SM 43% WI), its first horizontal well in the Woodford shale. The
Company plans to fracture stimulate the well in late July. St. Mary's one
operated drilling rig in the Centrahoma field will continue to test horizontal
drilling targets in the Cromwell sandstone and Wapanuka limestone.

ARKLATEX REGION

The Pate #1 (SM 100% WI) in the Garrison field in Shelby County, Texas, where
the Company owns 2,800 net acres, has reached total depth and is being prepared
for fracture stimulation in the Travis Peak. Positive test results could add
significant follow up activity in the field. In its horizontal James Lime play,
the Company completed the USA No. 9-H (SM 81% WI), the final well in its Huxley
field, at an initial rate of 2,500 MCFED, and the Martin Timber #1 Alt (SM 100%
WI) in its Spider field has been completed and is testing at a rate of 2,000
MCFED. Nine wells with an average working interest of 17% were completed in the
Elm Grove field during the second quarter at an average per well initial
production rate of 1,400 MCFED.

GULF COAST / PERMIAN REGION

The SML 24-1 ST (SM 25% RI) on the Company's fee lands in St. Mary Parish,
Louisiana has logged 111 feet of net pay. The well is currently being completed
with first production anticipated during the third quarter.

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                                UPDATED FORECAST

The Company updated its forecast for the second quarter and full year of 2005 as
follows:

                                        2nd Quarter                  Year
                                        -----------                  ----
Oil and gas production                21.0 - 21.5 BCFE         83.0 - 87.0 BCFE
Lease operating expenses,
   including production taxes and
   transportation                    $1.40 - $1.45/MCFE       $1.55 - $1.60/MCFE
General and administrative expense   $0.31 - $0.36/MCFE       $0.30 - $0.35/MCFE
Depreciation, depletion & amort. $1.52 - $1.57/MCFE       $1.54 - $1.60/MCFE

St. Mary estimates that its basis differential (the difference between estimated
realized oil and gas prices, before hedging, and the applicable NYMEX prices)
for the second quarter of 2005 will be $2.80 to $3.20 per barrel for oil and
$0.20 to $0.30 per MMBtu for gas.

During the second quarter the Company purchased 1,157,810 shares of its common
stock at an average cost of $24.44 per share. The Company has 3,863,590 shares
available for repurchase under its 6,000,000 share authorized program.

St. Mary also announced that David W. Honeyfield was appointed Chief Financial
Officer of the Company in addition to his duties as Vice President - Finance,
Secretary and Treasurer.

St. Mary is scheduled to release second quarter 2005 earnings after the close of
trading on the NYSE on August 3, 2005. The teleconference call to discuss second
quarter results is scheduled for August 4, 2005 at 8:00 am (MDT). The call
participation number is 888-424-5231. A digital recording of the conference call
will be available two hours after the completion of the call, 24 hours per day
through August 13 at 800-642-1687, conference number 3038634377. International
participants can dial 706-634-6088 to take part in the conference call and can
access a replay of the call at 706-645-9291, conference number 3038634377. In
addition, the call will be broadcast live at St. Mary's website at
www.stmaryland.com and the earnings press release and financial highlights
------------------
attachment will be available before the call at www.stmaryland.com under
                                                ------------------
"News-Press Releases." An audio recording of the conference call will be
available at that site through August 13.

This release contains forward looking statements within the meaning of
securities laws, including forecasts and projections. The words "will,"
"believe," "anticipate," "intend," "estimate," "forecast" and "expect" and
similar expressions are intended to identify forward looking statements. These
statements involve known and unknown risks, which may cause St. Mary's actual
results to differ materially from results expressed or implied by the forward
looking statements. These risks include such factors as the uncertain nature of
the expected benefits from the acquisition of oil and gas properties, the
volatility and level of oil and natural gas prices, unexpected drilling

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conditions and results, the risks of various exploration strategies, production
rates and reserve replacement, the imprecise nature of oil and gas reserve
estimates, drilling and operating service availability, uncertainties in cash
flow, the financial strength of hedge contract counterparties, the availability
of economically attractive exploration and development and property acquisition
opportunities and any necessary financing, competition, litigation,
environmental matters, the potential impact of government regulations, and other
such matters discussed in the "Risk Factors" section of St. Mary's 2004 Annual
Report on Form 10-K filed with the SEC. Although St. Mary may from time to time
voluntarily update its prior forward looking statements, it disclaims any
commitment to do so except as required by securities laws.

                                    PR-05-10
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