Washington D.C. 20549

                                    FORM 8-K

                Current Report Pursuant to Section 13 or 15(d) of
                       the Securities Exchange Act of 1934

                        Date of Report (Date of earliest
                                event reported):

                                August 21, 2007

                                TriCo Bancshares
             (Exact name of registrant as specified in its charter)

       California                   0-10661                   94-2792841
------------------------        ---------------          --------------------
     (State or other         (Commission File No.)         (I.R.S. Employer
     jurisdiction of                                      Identification No.)
incorporation or organization)

                 63 Constitution Drive, Chico, California 95973
              (Address of principal executive offices) (Zip Code)

Registrant's telephone number, including area code:(530) 898-0300

Check  the  appropriate  box  below  if the  Form  8-K  filing  is  intended  to
simultaneously  satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

 [ ] Written  communications  pursuant to Rule 425 under the  Securities Act (17
     CFR 230.425)

 [ ] Soliciting  material pursuant to rule 14a-12 under the Exchange Act (17 CFR

 [ ] Pre-commencement   communications  pursuant  to  Rule  14d-2(b)  under  the
     Exchange Act (17 CFR 240.14d-2(b))

 [ ] Pre-commencement   communications  pursuant  to  Rule  13e-4(c)  under  the
     Exchange Act (17 CFR 240.13e-4(c))

Item 8.01: Other Events
On August 21, 2007, the Board of Directors of TriCo Bancshares  (NASDAQ:  TCBK),
parent  company of Tri Counties  Bank,  announced  the  completion  of its stock
repurchase  plan  adopted  on July 31,  2003 and  amended  on April 9,  2004 and
adopted a new stock  repurchase  plan for the repurchase of up to 500,000 shares
of the common stock of TriCo  Bancshares  on the open  market.  These events are
described in greater  detail in the press  release dated August 21, 2007, a copy
of which is attached as Exhibit 99.1.

Item 9.01:  Financial Statements and Exhibits
(c)  Exhibits

     99.1  Press release dated August 21, 2007


Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.

                                            TRICO BANCSHARES

Date:  August 22, 2007        By:  /s/ Thomas J. Reddish
                                   Thomas J. Reddish, Executive Vice
                                   President and Chief Financial Officer
                                   (Principal Financial and Accounting

                                                                    Exhibit 99.1


PRESS RELEASE                                    Contact: Thomas J. Reddish,
FOR IMMEDIATE RELEASE                            Vice President & CFO
                                                 (530) 898-0300

CHICO,  Calif. - (August 21, 2007) - TriCo  Bancshares  (NASDAQ:  TCBK),  parent
company of Tri Counties  Bank,  today  announced that it has completed its stock
repurchase  plan  originally  adopted on July 31,  2003 and  amended on April 9,
2004. Under this plan, the Company  repurchased a total of 500,000 shares of its
common stock with the final 105,629 shares being repurchased  during August 2007
at an average price of $20.97 per share.  The Company has repurchased a total of
1,337,600 shares under repurchase plans since July 2000.

In  addition  the  Board  of  Directors  adopted  a new plan to  repurchase,  as
conditions  warrant,  up to 500,000 shares of the Company's  common stock on the
open  market.  The  timing of  purchases  and the  exact  number of shares to be
purchased will depend on market  conditions.  The 500,000 shares  authorized for
repurchase under this new stock repurchase plan represent  approximately 3.2% of
the Company's  15,814,662  currently  outstanding common shares.  This new stock
repurchase plan has no expiration date.

President and CEO Richard P. Smith stated that this new stock repurchase plan is
being implemented to provide  management with an additional tool to optimize the
Company's use of equity capital and enhance shareholder value. At June 30, 2007,
the Company's  total assets were  $1,887,027,000  and  shareholders'  equity was

TriCo Bancshares and Tri Counties Bank are  headquartered in Chico,  California.
Tri Counties Bank has a 31-year  history in the banking  industry.  Tri Counties
Bank operates 32 traditional  branch  locations and 23 in-store branch locations
in 22  California  counties.  Tri Counties  Bank offers  financial  services and
provides  a  diversified   line  of  products  and  services  to  consumers  and
businesses,  which include demand, savings and time deposits,  consumer finance,
online banking,  mortgage lending,  and commercial banking throughout its market
area.  It  operates  a  network  of 62 ATMs  and a  24-hour,  seven  days a week
telephone customer service center. Brokerage services are provided at the Bank's
offices by the Bank's association with Raymond James Financial, Inc. For further
information    please    visit   the   Tri    Counties    Bank    web-site    at