Exhibit 99.1

FOR IMMEDIATE RELEASE

April 27, 2017

                        

Columbia Banking System Announces First Quarter 2017 Results

and Quarterly Cash Dividend

Highlights

TACOMA, Washington, April 27, 2017 -- Hadley Robbins, Interim Chief Executive Officer of Columbia Banking System and Columbia Bank (NASDAQ: COLB) (“Columbia”), said today upon the release of Columbia’s first quarter 2017 earnings, “From a performance standpoint, we had a very good quarter. Our record first quarter performance was driven, in part, by increased net interest income, modest provision for loan losses, and increased noninterest income.” Mr. Robbins continued, “I am very proud of our team. The sudden passing of Melanie Dressel was a tragic loss for all of us; however, the strength of the culture Melanie built and epitomized so well shined in each of our team members when it mattered most. Our focus on caring for our customers, each other, and the communities we serve never wavered.”

Balance Sheet

Total assets at March 31, 2017 were $9.53 billion , an increase of $17.7 million from December 31, 2016 . Loans grew $14.7 million during the quarter as strong loan originations of $251.7 million were offset by payments. Loan production was diversified across the portfolio sectors, with growth primarily centered in commercial business and commercial real estate loans. Securities available for sale were $2.33 billion at March 31, 2017 , an increase of $52.8 million , or 2% from $2.28 billion at December 31, 2016 . Total deposits at March 31, 2017 were $8.09 billion , an increase of $29.4 million from December 31, 2016 . Core deposits comprised 96% of total deposits and were $7.79 billion at March 31, 2017 , an increase of $45.0 million from December 31, 2016 . The average cost of total deposits for the quarter was 0.04% , unchanged from the fourth quarter of 2016.

Income Statement

Net Interest Income

Net interest income for the first quarter of 2017 was $86.7 million , an increase of $938 thousand and $6.5 million from the linked and prior year periods, respectively. The linked quarter increase was principally from taxable securities income, whose yields benefited from a market-driven reduction in premium amortization. The increase from the prior year period was due to higher loan and securities volumes as well as the previously noted reduction in securities premium amortization. Incremental accretion income from purchased loans in the current period was $665 thousand lower than the prior year period. For additional information regarding net interest income, see the “Average Balances and Rates” table.

Noninterest Income

Noninterest income was $24.9 million for the first quarter of 2017 , an increase of $2.5 million compared to $22.3 million for the fourth quarter of 2017 . The linked quarter increase was principally due to a $1.5 million bank owned life insurance (“BOLI”) benefit as well as a $573 thousand benefit from re-measuring to zero our estimated mortgage repurchase liability, which were both recorded to other noninterest income. The repurchase liability was initially established with a prior acquisition. Compared to the first quarter of 2016 , noninterest income increased by $4.2 million due to the previously noted BOLI and mortgage repurchase benefits, as well as a $1.3 million increase in loan revenue due to higher fee income.

Noninterest Expense

Total noninterest expense for the first quarter of 2017 was $69.0 million , an increase of $4.0 million from $65.0 million for the fourth quarter of 2016 . After removing the effect of acquisition-related expenses, noninterest expense for the current quarter increased $2.9 million from the linked-quarter on the same basis. This increase was due to higher compensation and benefits as well as higher other noninterest expense. The increase in compensation and benefits was due to additional stock compensation expense related to the immediate vesting of certain restricted share awards and additional payroll taxes. The increase in other noninterest expense was due to the recording of an additional $850 thousand in expense related to the allowance for unfunded commitments and letters of credit during the current quarter, compared to a reversal of $200 thousand in the fourth quarter of 2016.

Compared to the first quarter of 2016 , noninterest expense increased $3.9 million , or 6% , from $65.1 million . After removing the effect of $1.4 million in acquisition-related expenses from the current quarter and $2.4 million from the prior year period, noninterest expense increased $5.0 million from the prior year period. The increase was due to higher compensation and benefits, which were driven by higher salaries as well as the previously mentioned stock compensation expenses. In addition, incentive expenses in the current quarter were higher based upon the Company's improved financial performance relative to the prior year period.

Net Interest Margin

Columbia’s net interest margin (tax equivalent) for the first quarter of 2017 was 4.20% , an increase of 9 basis points from the linked quarter and an increase of 7 basis points from the prior year period. The increase s from the linked and prior year quarters were due to higher interest income from taxable securities, which was driven by reduced amortization of premiums. Incremental accretion income was $4.1 million in the current period compared to $4.7 million in the prior year quarter.

Columbia’s operating net interest margin (tax equivalent) ⁽¹⁾ was 4.09% for the first quarter of 2017 , an increase of 10 and 6 basis points from the linked and prior year periods, respectively. As the previously mentioned lower premium amortization related to our purchased securities and not our acquired securities, this decrease in market-driven premium amortization also positively influenced our operating net interest margin (tax equivalent) ⁽¹⁾ .

Clint Stein, Columbia’s Executive Vice President and Chief Financial Officer, commented, “The rebound in our net interest margin during the quarter was primarily due to the reduction of overnight funds coupled with increased securities income resulting from lower amortization of premiums.” Mr. Stein continued, “The margin pressure associated with rates on new loan originations continues and any significant increase in competition for deposit relationships would further restrain margin expansion.”

The following table shows the impact to interest income resulting from income accretion on acquired loan portfolios as well as the net interest margin and operating net interest margin:

(1) Operating net interest margin (tax equivalent) is a non-GAAP financial measure. See the section titled “Non-GAAP Financial Measures” on the last pages of this earnings release for the reconciliation of operating net interest margin (tax equivalent) to net interest margin.

Asset Quality

At March 31, 2017 , nonperforming assets to total assets were 0.32% compared to 0.35% at December 31, 2016 . Total nonperforming assets decreased $3.7 million from the linked quarter due to a $2.2 million decrease in nonaccrual loans as well as a $1.5 million decrease in other real estate owned.

The following table sets forth information regarding nonaccrual loans and total nonperforming assets:

The following table provides an analysis of the Company's allowance for loan and lease losses:

The allowance for loan losses to period end loans was 1.14% at March 31, 2017 compared to 1.13% at December 31, 2016 . For the first quarter of 2017 , Columbia recorded a net provision for loan and lease losses of $2.8 million compared to a net provision of $18 thousand for the linked quarter and $5.3 million for the comparable quarter last year. The net provision for loan and lease losses recorded during the current quarter consisted of $3.1 million of provision for loan losses for loans, excluding PCI loans, partially offset by a provision recovery of $325 thousand for PCI loans.

Andy McDonald, Columbia’s Executive Vice President and Chief Credit Officer, commented, “We continue to see weakness in the agricultural sector; however, I am very pleased with overall portfolio performance. Annualized net charge offs for the quarter of 11 bps combined with a modest reduction in nonperforming assets is a testament to the hard work our bankers have put forth in keeping our credit cost low.”

Organizational Update

William Weyerhaeuser, Chairman of the Board of Columbia, commented, “The Board of Directors’ search for a permanent Chief Executive Officer is progressing as planned. We are actively evaluating both internal and external candidates to ensure the best possible individual to lead Columbia is placed in the role. At this stage of our search, it is too early to commit to a specific timeline for completing the process.”

Mr. Robbins commented, “Our pending acquisition of Pacific Continental Corporation is moving forward and progressing as we expected. Upon obtaining the necessary regulatory and shareholder approvals, we look forward to joining these two great companies together to the benefit of our customers, shareholders, and most importantly, the communities we serve.”

Cash Dividend Announcement

Columbia will pay a regular cash dividend of $0.22 per common share on May 24, 2017 to shareholders of record as of the close of business on May 10, 2017.

Conference Call Information

Columbia’s management will discuss the first quarter 2017 results on a conference call scheduled for Thursday, April 27, 2017 at 1:00 p.m. Pacific Daylight Time (4:00 p.m. EDT). Interested parties may listen to this discussion by calling 1-888-286-8956; Conference ID code #7691866.

A conference call replay will be available from approximately 4:00 p.m. PDT on April 27, 2017 through 9:00 p.m. PDT on May 4, 2017. The conference call replay can be accessed by dialing 1-888-286-8956 and entering Conference ID code #7691866.

About Columbia

Headquartered in Tacoma, Washington, Columbia Banking System, Inc. is the holding company of Columbia Bank, a Washington state-chartered full-service commercial bank with locations throughout Washington, Oregon and Idaho. For the tenth consecutive year, the bank was named in 2016 as one of  Puget Sound Business Journal's  "Washington's Best Workplaces." Columbia ranked in the top 30 on the 2017  Forbes  list of best banks.

More information about Columbia can be found on its website at www.columbiabank.com .

Note Regarding Forward-Looking Statements

This news release includes forward looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward looking statements include, but are not limited to, descriptions of Columbia’s management’s expectations regarding future events and developments such as future operating results, growth in loans and deposits, continued success of Columbia’s style of banking and the strength of the local economy. The words “will,” “believe,” “expect,” “intend,” “should,” and “anticipate” or the negative of these words or words of similar construction are intended in part to help identify forward looking statements. Future events are difficult to predict, and the expectations described above are necessarily subject to risks and uncertainties, many of which are outside our control, that may cause actual results to differ materially and adversely. In addition to discussions about risks and uncertainties set forth from time to time in Columbia’s filings with the Securities and Exchange Commission, available at the SEC’s website at www.sec.gov and the Company’s website at www.columbiabank.com, including the “Risk Factors,” “Business” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” sections of our annual reports on Form 10-K and quarterly reports on Form 10-Q, (as applicable), factors that may cause actual results to differ materially from those contemplated by such forward-looking statements include, among others, the following: (1) local, national and international economic conditions may be less favorable than expected or have a more direct and pronounced effect on Columbia than expected and adversely affect Columbia’s ability to continue its internal growth at historical rates and maintain the quality of its earning assets; (2) changes in interest rates could significantly reduce net interest income and negatively affect funding sources; (3) projected business increases following strategic expansion or opening or acquiring new branches may be lower than expected; (4) costs or difficulties related to the integration of acquisitions may be greater than expected; (5) competitive pressure among financial institutions may increase significantly; (6) legislation or regulatory requirements or changes may adversely affect the businesses in which Columbia is engaged; and (7) the proposed merger with Pacific Continental Corporation (“Pacific Continental”) may not close when expected or at all because required regulatory, shareholder or other approvals and other conditions to closing are not received or satisfied on a timely basis or at all, which may have an effect on the trading prices of Columbia’s stock. We believe the expectations reflected in our forward-looking statements are reasonable, based on information available to us on the date hereof. However, given the described uncertainties and risks, we cannot guarantee our future performance or results of operations and you should not place undue reliance on these forward-looking statements which speak only as of the date hereof. We undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by the federal securities laws. The factors noted above and the risks and uncertainties described in our SEC filings should be considered when reading any forward-looking statements in this release.

Additional Information

In connection with the Agreement and Plan of Merger, dated as of January 9, 2017, by and between Columbia Banking System, Inc. and Pacific Continental, Columbia has filed with the SEC a Registration Statement on Form S-4 that includes a Joint Proxy Statement of Columbia and Pacific Continental and a Prospectus of Columbia, as well as other relevant documents concerning the proposed transaction. Shareholders of Columbia and Pacific Continental are urged to carefully read the Registration Statement and the Joint Proxy Statement/Prospectus regarding the transaction in their entirety and any other relevant documents filed with the SEC, as well as any amendments or supplements to those documents, because they contain important information. Shareholders of Columbia and Pacific Continental are also urged to carefully review and consider each of Columbia’s and Pacific Continental’s public filings with the SEC, including but not limited to their Annual Reports on Form 10-K, their proxy statements, their Current Reports on Form 8-K and their Quarterly Reports on Form 10-Q.  A definitive Joint Proxy Statement/Prospectus will be sent to the shareholders of each institution seeking any required shareholder approvals.

The Joint Proxy Statement/Prospectus and other relevant materials filed with the SEC may be obtained free of charge at the SEC’s Website at http://www.sec.gov. PACIFIC CONTINENTAL AND COLUMBIA SHAREHOLDERS ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS AND THE OTHER RELEVANT MATERIALS BEFORE VOTING ON THE TRANSACTION.

Investors will also be able to obtain these documents, free of charge, from Pacific Continental by accessing Pacific Continental’s website at www.therightbank.com under the link “Investor Relations” or from Columbia at www.columbiabank.com under the tab “About” and then under the heading “Investor Relations.” Copies can also be obtained, free of charge, by directing a written request to Columbia, Attention: Corporate Secretary, 1301 A Street, Suite 800, Tacoma, Washington 98401-2156 or to Pacific Continental, Attention: Corporate Secretary, 111 West Seventh Avenue, P.O. Box 10727, Eugene Oregon 97440-2727.

Participants in Solicitation

Columbia and Pacific Continental and their directors and executive officers and certain other persons may be deemed to be participants in the solicitation of proxies from the shareholders of Pacific Continental or Columbia in connection with the transaction. Information about the directors and executive officers of Columbia and their ownership of Columbia common stock is set forth in the proxy statement for Columbia’s 2017 annual meeting of shareholders, as filed with the SEC on a Schedule 14A on April 13, 2017. Information about the directors and executive officers of Pacific Continental and their ownership of Pacific Continental common stock is set forth in Amendment No. 1 on Form 10-K/A to Pacific Continental’s Annual Report on Form 10-K for the year ended December 31, 2016, as filed with the SEC on April 19, 2017. Additional information regarding the interests of those participants and other persons who may be deemed participants in the solicitation may be obtained by reading the Joint Proxy Statement/Prospectus regarding the transaction. Free copies of this document may be obtained as described in the preceding paragraph.