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 30, 2004

                                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.)

                 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

[ ] 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 30, 2004, Tri Counties  Bank, a wholly owned  subsidiary of TriCo
Bancshares  (NASDAQ:  TCBK),  announced an aggressive  expansion  plan that will
bring six new branches to the Sacramento area and additional  branches to cities
as far south as Bakersfield by early 2005.

Item 9.01:  Financial Statements and Exhibits

(c) Exhibits

    99.1   Press release dated August 30, 2004


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 31, 2003        By:  /s/ Thomas J. Reddish
                                   Thomas J. Reddish, Vice President and
                                   Chief Financial Officer (Principal
                                   Financial and Accounting Officer)


Exhibit No.                Description
-----------                --------------------------------------------
    99.1                   Press release dated August 30, 2004

Exhibit 99.1

FOR IMMEDIATE RELEASE                         CONTACT:   Nicole Koebrich
                                                         Tri Counties Bank

       Largest Community Bank Headquartered North of Sacramento Continues
                Expansion Plans into California's Central Valley

CHICO,  Calif.  - (August 30, 2004) -Tri  Counties Bank is bringing its hometown
banking  philosophy to  communities  throughout  the Central  Valley  through an
aggressive  expansion  plan that will bring six new  branches to the  Sacramento
area and  additional  branches  to cities as far south as  Bakersfield  by early

The Chico-based Tri Counties Bank, a wholly owned subsidiary of TriCo Bancshares
(NASDAQ:  TCBK),  is expanding  its  Northern  California  banking  operation in
Sacramento  primarily  through Raley's stores.  Five of the new branches will be
located inside Raley's stores in Woodland,  Folsom, Lincoln, Elk Grove and North
Natomas.  All five in-store  branches  will offer full service  banking and will
operate  just  like a  traditional  branch.  Plans are also  underway  for a new
traditional  branch  that will  increase  Tri  Counties  Bank's  presence in the
Roseville  area.  Tri  Counties  Bank  currently  operates  4  branches  in  the
Sacramento area.

"In-store  banking has been a very  effective way for Tri Counties Bank to enter
new markets, and introduce new customers to our bank in a supermarket where they
are  already  doing their  shopping,"  said Andrew  Mastorakis,  executive  vice
president of Retail Banking for Tri Counties Bank.  "In-store banking has proven
to be a great way for us to  penetrate a new market and grow our  customer  base
much quicker and at a lower cost. Additionally,  we're able to provide service 7
days a week, which customers value as a huge convenience."

All  in-store  branches  are open  seven days a week and until  7p.m.  every day
except Sundays, when they are open until 5p.m.

Plans have also been set forth to expand and  re-locate  the Tri  Counties  Bank
business centers in Bakersfield,  Arden Fair, Modesto and Visalia,  all of which
have out grown the current  locations.  The new  locations  for each office will
accommodate  future  growth,  enhance  consumer  banking  services  and  support
branches that will be opening in those areas through the ongoing expansion.

"We are a traditional bank, born and raised in Chico, one of California's  great
small  towns," said Rick Smith,  president  and CEO of Tri Counties  Bank.  "Our
success in the  communities we serve north of Sacramento has allowed us to carry
over our banking philosophy throughout  California's booming Central Valley. The
Central  Valley is  booming,  and the growing  communities  there value the same
banking principles of those we've been serving for the last 29 years."

Tri Counties Bank  currently  operates 33  traditional  branches and 13 in-store
branches  throughout  California.  Four of those  branches  are  located  in the
Sacramento  Area,  and seven span from  Modesto to  Bakersfield  in the  Central
Valley.  The bank's  expansion  plans include  several  additional  locations in
markets throughout the Central Valley.

TriCo Bancshares and Tri Counties Bank are  headquartered  in Chico,  Calif. Tri
Counties  Bank has a 29-year  history in the  banking  industry.  It operates 33
traditional  branch  locations and 13 in-store branch locations in 21 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 58
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 http://www.tricountiesbank.com.