Exhibit 99.1

TRICO BANCSHARES ANNOUNCES QUARTERLY RESULTS

CHICO, Calif. – (October 28, 2011) – TriCo Bancshares (NASDAQ: TCBK) (the “Company”), parent company of Tri Counties Bank (the “Bank”), today announced earnings of $6,470,000 for the quarter ended September 30, 2011. This compares with earnings of $1,000 the Company reported for the quarter ended September 30, 2010. Diluted earnings per share for the quarter ended September 30, 2011 were $0.40 compared to diluted earnings per share of $0.00 for the quarter ended September 30, 2010. Diluted earnings per share for the nine months ended September 30, 2011 and 2010 were $0.75 and $0.18, respectively, on earnings of $12,041,000 and $2,879,000, respectively.

Total assets of the Company increased $258,849,000 (11.6%) to $2,488,467,000 at September 30, 2011 from $2,229,618,000 at September 30, 2010. Total loans of the Company increased $122,835,000 (8.5%) to $1,575,627,000 at September 30, 2011 from $1,452,792,000 at September 30, 2010. Total deposits of the Company increased $231,682,000 (12.3%) to $2,120,223,000 at September 30, 2011 from $1,888,541,000 at September 30, 2010.

The following is a summary of the components of Company’s consolidated net income for the periods indicated:

Included in the Company’s results for the three and nine month periods ended September 30, 2011 is the acquisition by Tri Counties Bank of the banking operations of Citizens Bank of Northern California (“Citizens”), Nevada City, California from the FDIC under a whole bank purchase and assumption agreement without loss sharing on September 23, 2011. The assets acquired and liabilities assumed in the Citizens acquisition have been accounted for under the acquisition method of accounting (formerly the purchase method).

A summary of the net assets received in the Citizens acquisition, at their estimated fair values on September 23, 2011, is presented below:

As a result of the Citizens acquisition on September 23, 2011, the Company recorded a before-tax bargain purchase gain of $7,575,000 ($4,390,000 after-tax) representing the excess of the estimated fair value of the assets acquired over the estimated fair value of the liabilities assumed. The before-tax bargain purchase gain is recorded in noninterest income and the related tax effect ($3,185,000) is recorded in tax expense for the three and nine month periods ended September 30, 2011.

A summary of the estimated fair value adjustments resulting in the bargain purchase gain in the Citizens acquisition are presented below:

The Company recorded a provision for loan loss of $5,069,000 during the three months ended September 30, 2011 compared to $10,814,000 during the three months ended September 30, 2010. This decrease in the provision from the year-ago period is mainly due to the continued stabilization of nonperforming originated loan totals and their related charge-offs when compared to the year-ago period. Loan charge-offs, net of recoveries, were $3,731,000 during the three months ended September 30, 2011 compared to $10,474,000 during the year-ago period.

The following table shows the components of net interest income and net interest margin on a fully tax-equivalent (FTE) basis for the periods indicated:

ANALYSIS OF CHANGE IN NET INTEREST MARGIN ON EARNING ASSETS

(unaudited, in thousands)

The operations of Citizens from September 23, 2011 to September 30, 2011 added approximately $271,000 and $14,000 to interest income and interest expense, respectively, and approximately $12,800,000 and $18,800,000 to average interest-earning asset and liability balances, respectively, during the three months ended September 30, 2011. These contributions to interest income and interest expense from the Citizens acquisition represent an average interest-earning asset yield of approximately 8.5%, and an average interest-bearing liabilities rate of 0.30%. The recognition of interest income from the acquired Citizens loans may fluctuate greatly depending on changes in actual and expected future cash flows of such loans. One week of activity may not be a good indicator of future activity.

As the operations of Citizens did not have a major impact on net interest income and net interest margin during the three months ended September 30, 2011, the change in net interest margin (FTE) from 4.63% during the three months ended September 30, 2010 to 4.34% in the current quarter is indicative of continued weak loan demand and investment yields that have been unattractive given their interest rate risk profile. As shown in the “Selected Financial Ratios” section of the tables below, the Company’s net interest margin has been stable and improving slightly over the last four quarterly periods beginning at 4.30% during the quarter ended December 31, 2010.

Noninterest income increased $7,560,000 to $14,723,000 during the three months ended September 30, 2011 when compared to the three months ended September 30, 2010. In addition to the $7,575,000 bargain purchase gain from the Citizens acquisition on September 23, 2011, the operations of Citizens from September 23, 2011 to September 30, 2011 added income of $28,000 to service charges on deposit accounts. The following table presents the key components of noninterest income for the periods indicated:

Noninterest expense increased $349,000 to $20,873,000 during the three months ended September 30, 2011 when compared to the three months ended September 30, 2010. The operations of Citizens from September 23, 2011 to September 30, 2011 added $118,000 to salaries expense and $13,000 to other noninterest expense. There were no significant acquisition expenses associated with the Citizens acquisition recorded during the three months ended September 30, 2011. The following table presents the key components of noninterest expense for the periods indicated:

In addition to the historical information contained herein, this press release may contain certain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. The reader of this press release should understand that all such forward-looking statements are subject to various uncertainties and risks that could affect their outcome. The Company’s actual results could differ materially from those suggested by such forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, variances in the actual versus projected growth in assets, return on assets, interest rate fluctuations, economic conditions in the Company’s primary market area, demand for loans, regulatory and accounting changes, loan losses, expenses, rates charged on loans and earned on securities investments, rates paid on deposits, competition effects, fee and other noninterest income earned as well as other factors detailed in the Company’s reports filed with the Securities and Exchange Commission which are incorporated herein by reference, including the Form 10-K for the year ended December 31, 2010. These reports and this entire press release should be read to put such forward-looking statements in context and to gain a more complete understanding of the uncertainties and risks involved in the Company’s business. Any forward-looking statement may turn out to be wrong and cannot be guaranteed. The Company does not intend to update any of the forward-looking statements after the date of this release.

TriCo Bancshares and Tri Counties Bank are headquartered in Chico, California. Tri Counties Bank has a 36-year history in the banking industry. It operates 41 traditional branch locations and 27 in-store branch locations in 23 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 76 ATMs and a 24-hour, seven days-a-week telephone customer service center. Brokerage services are provided by the Bank’s investment services affiliate, Raymond James Financial Services, Inc. For further information please visit the Tri Counties Bank web site at http://www.tricountiesbank.com.

TRICO BANCSHARES - CONSOLIDATED FINANCIAL DATA

(Unaudited. Dollars in thousands, except share data)

TRICO BANCSHARES - CONSOLIDATED FINANCIAL DATA

(Unaudited. Dollars in thousands)