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):

                                   May 4, 2005

                                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

Richard P. Smith, President and Chief Executive Officer of TriCo Bancshares (the
"Company"),  has  informed the Company that on May 4, 2005,  he  terminated  his
pre-arranged stock trading plan previously  adopted on March 30, 2005,  relating
to the sale of up to 37,500 shares of the Company's  common stock.  The plan was
adopted in accordance with the guidelines  specified under Rule 10b5-1 under the
Securities Exchange Act of 1934, as amended. No trades were made under the Plan.
Instead,  Mr. Smith plans to sell approximately  37,500 shares upon his exercise
of options  expiring in June 2005 during the Company's  current "trading window"
pursuant to the Company's Policy Concerning Trading in Company Securities.

Mr.  Smith  currently  reports  beneficial  ownership  of 525,386  shares of the
Company's  common stock  including  vested and  non-vested  stock  options,  but
excluding shares held by the Company's ESOP of which Mr. Smith is a trustee. The
37,500  shares  which  are  anticipated  to  be  sold  by  Mr.  Smith  represent
approximately 7% of his shareholdings.

Mr. Smith has confirmed to the Company that, as required by securities  laws, he
will  promptly  publicly  disclose  any option  exercises  and/or stock sales of
Company common stock made by him.  Except as may be required by law, the Company
does not undertake to report plans by other Company  officers or directors,  nor
to report  modifications,  terminations,  transactions or other activities under
the plans of any officer or director.


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:  May 4, 2005            By:  /s/ Thomas J. Reddish
                                   Thomas J. Reddish, Executive Vice
                                   President and Chief Financial Officer
                                   (Principal Financial and Accounting