CORRECTING and REPLACING Tri-Valley Corporation Reports 11% Increase in Revenues from Oil and Gas Operations in the First Quarter of 2011

Please replace the release with the following corrected version due to
multiple revisions to the 'Costs and Expenses' section of the table with
the header 'TRI-VALLEY CORPORATION CONSOLIDATED STATEMENT OF OPERATIONS.'

The corrected release reads:

TRI-VALLEY CORPORATION REPORTS 11% INCREASE IN REVENUES FROM OIL AND
GAS OPERATIONS IN THE FIRST QUARTER OF 2011

Stockholders′ Equity Increased 50% Over 2010 Year End

Conference
Call Today at 4:30 p.m. Eastern Time

Tri-Valley Corporation (NYSE Amex: TIV) today announced its financial
results for the first quarter ended March 31, 2011. Oil and gas revenues
grew 11% to $658,000 in the first quarter of 2011 compared with $590,000
in the first quarter of 2010, due to higher oil prices and increased oil
production. Net production in the recent first quarter totaled 7,004
barrels of oil compared with 6,110 barrels in the same quarter of 2010,
an increase of 15%. Net production costs increased 7% in the 2011 first
quarter compared with the same quarter a year ago.

'These results demonstrate the strong leverage potential of our oil and
gas business model, following the initiatives we put in place last year
to increase oil production and reduce costs,? said Maston N. Cunningham,
Tri-Valley′s President and CEO. 'Oil and gas revenues from operations
increased 11% in the quarter with a corresponding increase in production
expenses of just 7%. With higher oil prices and our success in driving
additional production at both our Pleasant Valley and Claflin oil
projects, we anticipate continued revenue growth and improvement on our
bottom-line during 2011.?

'In Alaska, we continue to move forward on our efforts to find
operational and financial partners to assist in the exploration and
development of our two gold exploration properties ? Richardson and
Shorty Creek. Finally, with the successful raise of capital during the
quarter through the sale of common stock under our at-the-market ('ATM?)
equity offering programs with C. K. Cooper & Company, we ended the first
quarter with $1.6 million in cash, an increase of $1 million from the
level at the end of December 2010, and stockholders′ equity of $9.2
million at March 31, 2011, compared with $6.2 million and $0.9 million
at December 31, 2010, and March 31, 2010, respectively.?

Operational highlights during the first quarter of 2011 included:

• 
  Implemented actions to reduce general and administrative costs by
  approximately $1.0 million annually,
  
• 
  Exchanged and cancelled the remaining Series A and Series B warrants
  associated with the April 6, 2010, registered direct offering,
  reducing exposure to future dilution and providing financial
  flexibility,
  
• 
  Embarked on the first phase of the extended development and enhanced
  oil production at the Claflin oil project in the Edison oil field near
  Bakersfield, California,
  
• 
  Completed two at-the-market ('ATM?) equity offering programs with C.
  K. Cooper & Company acting as agent, raising gross proceeds that in
  aggregate totaled $6.0 million with total net proceeds of $5.6 million,
  
• 
  Reached a favorable settlement of lease termination litigation brought
  in 2009 by the lessors of the Lenox Ranch oil and gas leases located
  in the Pleasant Valley oil sands project, near Oxnard, California, and
  
• 
  Resolved the continued listing deficiency with the NYSE Amex.
  

'We continued to make progress on several key initiatives in the second
quarter. We completed a $5 million private placement that allows us to
continue the development of Claflin. As of April 30, 2011, we had $6.3
million in cash. We completed Phase One of our Claflin project, drilling
8 of 22 new wells planned at the project and expect to begin production
from some of the new wells later this month following an initial steam
injection cycle. At Pleasant Valley, we continue the preparations for
the implementation of SAGD this year that we believe will result in
improved oil recovery. We remain committed to our goal of generating
1,000 barrels of oil per day from our two oil fields in California by
year-end.?

'Discussions with representatives from our OPUS partnership are ongoing,
and we hope to reach an agreement this year that will facilitate the
financing and development of the Pleasant Valley oil sands project which
will accrete value to both Tri-Valley and our OPUS partners. We are
optimistic that with an improved financial performance, outlook for
continued growth, and a path towards the monetization of our Alaskan
mineral assets, we should be well-positioned to generate enhanced
valuation for our shareholders,? concluded Mr. Cunningham.

First Quarter Financial Highlights

Total revenues for the first quarter of 2011 increased to $721,000
compared with $1.2 million in the first quarter of 2010, which included
$591,000 from gains on the sales of assets. Oil and gas revenues
increased 11% to $658,000.

Total costs and expenses decreased 6% to $3.2 million in the first
quarter of 2011 compared with $3.4 million in the prior year′s first
quarter. The decrease was largely due to a significant reduction in
warrant expense, as well as, lower mining exploration expenses and
depreciation and interest expense, partially offset by an increase in
general and administrative expenses. The increase in general and
administrative expense reflected higher legal expenses from ongoing
litigation related to our Pleasant Valley leases and capital formation
fees incurred in the recent first quarter, partially offset by lower
total salary and benefits expenses, attributable to cost reductions
initiated during the first quarter of 2010. Oil production costs
increased 7% in the first quarter.

The net loss in the recent first quarter was $2.5 million, or $0.05 per
share, compared with a net loss of $2.2 million, or $0.07 per share in
the first quarter of 2010. The increase in the net loss of $275,000 in
the 2011 first quarter was primarily attributable to the lack of
comparable gains on sales of assets in the prior year′s first quarter.

Conference Call

The Company has scheduled a conference call to discuss its first quarter
2011 results and current business developments today, May 9, 2011, at
4:30 p.m. ET. To access the call, please dial 877-941-0844. To access
the live webcast of the call, visit Tri-Valley′s website at www.tri-valleycorp.com.

An audio replay will be available for seven days following the call at
800-406-7325.  The password required to access the replay is 4436246#. An
archived webcast will also be available at www.tri-valleycorp.com.

About Tri-Valley

Tri-Valley Corporation explores for and produces oil and natural gas in
California and has two exploration-stage gold properties in Alaska.
Tri-Valley is incorporated in Delaware and is publicly traded on the
NYSE Amex exchange under the symbol 'TIV.' Our Company website, which
includes all SEC filings, is www.tri-valleycorp.com.

Note Regarding Forward-Looking Statements

All statements contained in this press release that refer to future
events or other non-historical matters are forward-looking statements.We have attempted to identify forward-looking statements by
terminology including 'anticipates,? 'believes,? 'can,? 'continue,?
'could,? 'estimates,? 'expects,? 'hope,? 'intends,? 'may,? 'plans,?
'potential,? or 'predicts,? or the negative of these terms or other
comparable terminology. Although we do not make forward-looking
statements unless we believe we have a reasonable basis for doing so, we
cannot guarantee their accuracy. These statements are only predictions
based on management′s expectations as of the date of this press release,
and involve known and unknown risks, uncertainties and other factors,
including: our ability to obtain additional funding; fluctuations in oil
and natural gas prices; imprecise estimates of oil reserves; drilling
hazards such as equipment failures, fires, explosions, blow-outs, and
pipe failure; shortages or delays in the delivery of drilling rigs and
other equipment; problems in delivery to market; adverse weather
conditions; compliance with governmental and regulatory requirements;
geographical concentration of oil and gas reserves in the State of
California; changes in, or inability to enter into or maintain,
strategic and joint venture partnerships; pending and threatened
lawsuits against us; potential rescission rights stemming from our
potential violation of Section 5 of the Securities Act of 1933; and such
other risks and factors that are discussed in our filings with the
Securities and Exchange Commission, or SEC, from time to time,
including, but not limited to, under 'Part I, Item 2. Management′s
Discussion and Analysis of Financial Condition and Results of
Operations? and 'Part II, Item 1A. Risk Factors,? contained in the
Company′s Quarterly Report on Form 10-Q for the quarter ended March 31,
2011, filed with the SEC on May 9, 2011, and under 'Part I, Item 1A.
Risk Factors? and 'Part II, Item 7. Management′s Discussion and Analysis
of Financial Condition and Results of Operations,? contained in the
Company′s Annual Report on Form 10-K for the yearended December
31, 2010, filed with the SEC on March 22, 2011.Except as
required by law, we undertake no obligation to update or revise publicly
any of the forward-looking statements after the date of this press
release to conform such statements to actual results or to reflect
events or circumstances occurring after the date of this press release.

Company Contact:

Tri-Valley Corporation

John
Durbin, 661-864-0500

jdurbin@tri-valleycorp.com

or

Investor
Contacts:

EVC Group, Inc.

Doug Sherk/Jenifer Kirtland,
415-896-6820

dsherk@evcgroup.com

jkirtland@evcgroup.com

or

Media
Contact:

Chris Gale, 646-201-5431

cgale@evcgroup.com