Exhibit 99.1

TRICO BANCSHARES ANNOUNCES QUARTERLY RESULTS

CHICO, Calif. – (July 23, 2015) – TriCo Bancshares (NASDAQ: TCBK) (the “Company”), parent company of Tri Counties Bank, today announced earnings of $11,366,000, or $0.49 per diluted share, for the three months ended June 30, 2015. For the three months ended June 30, 2014 the Company reported earnings of $4,859,000, or $0.30 per diluted share. Diluted shares outstanding were 22,980,033 and 16,310,463 for the three months ended June 30, 2015 and 2014, respectively.

On October 3, 2014, TriCo completed its acquisition of North Valley Bancorp. North Valley Bancorp was headquartered in Redding, California, and was the parent of North Valley Bank that had approximately $935 million in assets and 22 commercial banking offices in Shasta, Humboldt, Del Norte, Mendocino, Yolo, Sonoma, Placer and Trinity Counties in Northern California. In connection with the acquisition, North Valley Bank was merged into Tri Counties Bank. Beginning on October 4, 2014, the effect of revenue and expenses from the operations of North Valley Bancorp, and 6,575,550 shares of TriCo Bancshares common shares issued in consideration of the merger are included in the results of the Company.

On October 25, 2014, North Valley Bank’s electronic customer service and other data processing systems were converted into Tri Counties Bank’s systems. Between January 7, 2015 and January 21, 2015, four Tri Counties Bank branches and four former North Valley Bank branches were consolidated into other Tri Counties Bank or other former North Valley Bank branches.

Included in the results of the Company for the three months ended June 30, 2015 and 2014 were $0 and $418,000, respectively, of nonrecurring noninterest expenses related to the merger with North Valley Bancorp of which $0 and $241,000, respectively, were not deductible for income tax purposes. Excluding these nonrecurring merger related expenses, but including the revenue and other expenses from the operations of North Valley Bancorp from April 1, 2015 to June 30, 2015, diluted earnings per share for the three months ended June 30, 2015 and 2014 would have been $0.49 and $0.33, respectively, on earnings of $11,366,000 and $5,342,000, respectively.

The following is a summary of certain of the Company’s consolidated assets and deposits as of the dates indicated:

Included in the changes in the Company’s assets and deposits from June 30, 2014 to June 30, 2015 is the effect of those assets and deposits acquired as part of the North Valley Bancorp acquisition on October 3, 2014. The following table shows the fair value of consideration transferred, the total identifiable net assets acquired and the resulting goodwill related to the North Valley Bancorp acquisition:

The following is a summary of the components of the Company’s consolidated net income, average common shares, and average diluted common shares outstanding for the periods indicated:

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, dollars in thousands)

Net interest income (FTE) during the three months ended June 30, 2015 increased $11,302,000 (41.2%) from the same period in 2014 to $38,715,000. The increase in net interest income (FTE) was due primarily to a $641,803,000 (37.4%) increase in the average balance of loans to $2,355,864,000, and a $569,136,000 (115%) increase in the average balance of investments to $1,064,142,000 that were partially offset by a 26 basis point decrease in the average yield on loans from 5.70% during the three months ended June 30, 2014 to 5.44% during the three months ended June 30, 2015, and an eight basis point decrease in the average yield on investments from 3.06% during the three months ended June 30, 2014 to 2.97% during the three months ended June 30, 2015. The $641,803,000 increase in average loan balances from the year ago quarter was primarily due to the addition of $499,327,000 of loans through the acquisition of North Valley Bancorp on October 4, 2014, and moderate to strong loan demand during the three and six months ended June 30, 2015. The $569,136,000 increase in average investment balances from the year-ago quarter was primarily due to the use of cash at the Federal Reserve and other banks to purchase investments and the addition of $212,616,000 of investments through the acquisition of North Valley Bancorp on October 4, 2014. The decrease in average loan yields is due primarily to declines in market yields on new and renewed loans compared to yields on repricing, maturing, and paid off loans. The decrease in average investment yields is due primarily to declines in market yields on new investments compared to yields on existing investments. The increases in average loan and investment balances added $9,146,000 and $4,381,000, respectively, to net interest income (FTE) while the decreases in average loan and investment yields reduced net interest income (FTE) by $1,560,000 and $264,000, respectively, when compared to the year-ago quarter. Included in interest income during the three months ended June 30, 2015 was a special cash dividend of $626,000 from the Company’s investment in Federal Home Loan Bank stock, and $2,133,000 of discount accretion from purchased loans compared to $1,504,000 of discount accretion from purchased loans during the three months ended June 30, 2014.

Loans acquired through purchase or acquisition of other banks are classified by the Company as Purchased Not Credit Impaired (PNCI), Purchased Credit Impaired – cash basis (PCI – cash basis), or Purchased Credit Impaired – other (PCI – other). Loans not acquired in an acquisition or otherwise “purchased” are classified as “originated”. Often, such purchased loans are purchased at a discount to face value, and part of this discount is accreted into (added to) interest income over the remaining life of the loan. Generally, as time goes on, the effect of this discount accretion decreases as these purchased loans mature or pay off early. Further details regarding interest income from loans, including fair value discount accretion, may be found under the heading “Supplemental Loan Interest Income Data” in the Consolidated Financial Data table at the end of this press release.

The Company recorded a reversal of provision for loan losses of $633,000 during the three months ended June 30, 2015 compared to a provision for loan losses of $1,708,000 during the three months ended June 30, 2014. The reversal of provision for loan losses during the three months ended June 30, 2015 was due to a $600,000 decrease in the required allowance for loan losses from $36,055,000 at March 31, 2015 to $35,455,000 at June 30, 2015 and $33,000 of net recoveries during the three months ended June 30, 2015. The decrease in required allowance for loan losses was due primarily to reduced impaired loans, improvements in estimated cash flows and collateral values for the remaining and newly impaired loans, and reductions in historical loss factors that, in part, determine the required loan loss allowance for performing loans in accordance with the Company’s allowance for loan losses methodology; and despite a $72,879,000 increase in loan balances from $2,320,883,000 at March 31, 2015 to $2,393,762,000 at June 30, 2015. During the three months ended June 30, 2015, nonperforming loans decreased $9,337,000 (19.0%) to $39,880,000, and represented a decrease from 2.12% to 1.67% of loans outstanding as of March 31, 2015 and June 30, 2015, respectively.

The following table presents the key components of noninterest income for the periods indicated:

Noninterest income increased $4,203,000 (53.4%) to $12,080,000 during the three months ended June 30, 2015 when compared to the three months ended June 30, 2014. The increase in noninterest income was due primarily to an increase in service charges on deposit accounts of $913,000 (33.5%) to $3,637,000, an increase in ATM fees and interchange revenue of $1,191,000 (54.3%) to $3,383,000, an increase in change in value of mortgage servicing rights (MSRs) of $872,000 to a positive $521,000 from a negative $351,000, and an increase in other noninterest income of $425,000 (93.8%) to $878,000 compared to the year-ago quarter. These increases, and the increases in other categories of noninterest income noted in the table above, are primarily the result of the acquisition of North Valley Bancorp on October 4, 2014. An increase in interest rates during the three months ended June 30, 2015 resulted in a decrease in estimated prepayment speeds of serviced loans, that in turn resulted in increased expected servicing cash flows, and thus, a higher value of such servicing rights.

The following table presents the key components of the Company’s noninterest expense for the periods indicated:

Salary and benefit expenses increased $3,925,000 (29.5%) to $17,242,000 during the three months ended June 30, 2015 compared to the three months ended June 30, 2014. Base salaries, incentive compensation and benefits & other compensation expense increased $2,494,000 (27.7%), $185,000 (15.4%), and $1,246,000 (40.1%), respectively, to $11,502,000, $1,390,000 and $4,350,000, respectively, during the three months ended June 30, 2015. The increases in these categories of salary and benefits expense are primarily due to the Company’s acquisition of North Valley Bancorp on October 4, 2014. The average number of full-time equivalent staff increased 218 (30.0%) from 726 during the three months ended June 30, 2014 to 944 for the three months ended June 30, 2015.

Other noninterest expense increased $3,395,000 (28.8%) to $15,194,000 during the three months ended June 30, 2015 compared to the three months ended June 30, 2014. The increase in other noninterest expense was primarily due to the Company’s acquisition of North Valley Bancorp on October 4, 2014. Nonrecurring merger expenses related to the North Valley Bancorp acquisition totaling $0 and $418,000 are included in other noninterest expense for the three months ended June 30, 2015 and 2014, respectively. As of March 31, 2015, the Company had substantially completed all of its previously planned facility consolidations related to the North Valley Bancorp acquisition. Subsequent to March 31, 2015, and following a thorough analysis of profitability and market opportunity, the Bank identified five additional branches for closure. Two of those branches are former North Valley Bank branches. As of June 30, 2015 one of the five additional branches slated for closure has been closed. The Bank expects the four remaining branches will be closed by September 30, 2015.

Richard Smith, President and CEO of the Company commented, “The benefits from the acquisition of North Valley Bancorp continued to materialize in many areas in the second quarter of 2015. Customer retention related to the acquisition has exceeded our internal forecasts. Loan growth from all of our geographic markets was strong, leading to higher levels of interest income. Noninterest income from interchange fees, service charges, service fees and mortgage lending all increased due to the added customers from North Valley Bank and increased overall business activities. The economies in our market areas continue to improve leading to greater opportunities for lending activities and our nonperforming loans also decreased significantly during the quarter. The integration of the North Valley transaction is mostly complete and the merger continues to provide us forward momentum.”

Smith added, “We continue to evaluate the ever changing needs of our customers as we invest in technology solutions favored by our customers. This also provides us with the opportunity to refine our branch network to improve our operating efficiencies. As we move forward, the balance between technology solutions and branch offices will be determined by customers’ activities and preferences. As previously announced, we will close four branches in the third quarter of 2015.”

In addition to the historical information contained herein, this press release may contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements are subject to various uncertainties and risks that could affect their outcome. The Company’s actual results could differ materially. 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, the Company’s ability to effectively integrate the business of North Valley Bancorp, 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, 2014. 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. The Company does not intend to update any of the forward-looking statements after the date of this release.

Established in 1975, Tri Counties Bank is a wholly-owned subsidiary of TriCo Bancshares (NASDAQ: TCBK) headquartered in Chico, California, providing a unique brand of customer Service with Solutions available in traditional stand-alone and in-store bank branches in communities throughout Northern and Central California. Tri Counties Bank provides an extensive and competitive breadth of consumer, small business and commercial banking financial services, along with convenient around-the-clock ATM, online and mobile banking access. Brokerage services are provided by the Bank’s investment services through affiliation with Raymond James Financial Services, Inc. Visit www.TriCountiesBank.com to learn more.

TRICO BANCSHARES - CONSOLIDATED FINANCIAL DATA

(Unaudited. Dollars in thousands, except share data)

TRICO BANCSHARES - CONSOLIDATED FINANCIAL DATA

(Unaudited. Dollars in thousands)