Exhibit 99.1

FOR IMMEDIATE RELEASE

July 27, 2017

                        

Columbia Banking System Announces Second Quarter 2017 Results

and Quarterly Cash Dividend

Highlights

TACOMA, Washington, July 27, 2017 -- Hadley Robbins, President and Chief Executive Officer of Columbia Banking System and Columbia Bank (NASDAQ: COLB) (“Columbia”), said today upon the release of Columbia’s second quarter 2017 earnings, “I’m pleased with our record setting earnings for the quarter, especially in light of the impact of the $2.4 million expense we recognized to terminate our FDIC loss sharing agreements, which when combined with the $1.0 million of acquisition-related expense recorded in the quarter, reduced our earnings per share by $0.04.” Mr. Robbins continued, “Our record first half 2017 earnings is a direct reflection on the efforts of our bankers, who remain focused on developing new relationships while deepening existing ones.”

Balance Sheet

Total assets at June 30, 2017 were $9.69 billion , an increase of $157.8 million from March 31, 2017 . Loans grew $194.9 million during the quarter due to strong loan originations of $316.2 million and seasonal increases in line utilization. Securities available for sale were $2.26 billion at June 30, 2017 , a decrease of $66.7 million , or 3% from $2.33 billion at March 31, 2017 . Total deposits at June 30, 2017 were $8.07 billion , a decrease of $16.4 million from March 31, 2017 . Core deposits comprised 96% of total deposits and were $7.72 billion at June 30, 2017 , a decrease of $72.8 million from March 31, 2017 . The average cost of total deposits for the quarter was 0.05% , an increase of one basis point from the first quarter of 2017 .

Income Statement

Net Interest Income

Net interest income for the second quarter of 2017 was $86.2 million , a decrease of $514 thousand from the linked period and an increase of $4.0 million from the prior year period. The linked quarter decrease was principally from taxable securities income, whose yields during the first quarter of 2017 benefited from a market-driven reduction in premium amortization. Also contributing to the decrease was incremental accretion from purchased loans, which was $956 thousand lower than the linked period. The increase from the prior year period was due to higher loan and securities volumes, partially offset by lower incremental accretion. Incremental accretion income from purchased loans in the current period was $1.3 million 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 $24.1 million for the second quarter of 2017 , a decrease of $724 thousand compared to $24.9 million for the first quarter of 2017 . The linked quarter decrease was principally due to lower bank owned life insurance (“BOLI”) benefits in the current period as well as a $573 thousand benefit from re-measuring our mortgage repurchase liability in the linked period. Both the BOLI and mortgage repurchase benefits were recorded to other noninterest income. Compared to the second quarter of 2016 , noninterest income increased by $2.2 million due to lower expenses from the FDIC loss-sharing asset as well as higher other noninterest income, principally from a current quarter BOLI benefit of $430 thousand, with no such BOLI benefit in the prior year period.

Noninterest Expense

Total noninterest expense for the second quarter of 2017 was $68.9 million , a decrease of $119 thousand from the first quarter of 2017 . The small improvement resulted from lower compensation costs being offset by the $2.4 million charge from early termination of our FDIC loss-sharing agreements; the early termination charge was recognized in other noninterest expense. The lower compensation costs stemmed from additional stock compensation expense recognized in the linked quarter due to the immediate vesting of certain restricted share awards as well as additional payroll taxes.

Compared to the second quarter of 2016 , noninterest expense increased $5.1 million , or 8% , from $63.8 million . The increase was due to the previously noted charge from early termination of loss-sharing agreements as well as $1.0 million of acquisition-related expenses recognized in the current quarter. In addition, legal and professional fees were higher due to costs from both our investment in a customer relationship management application and the search for a permanent Chief Executive Officer.

Net Interest Margin

Columbia’s net interest margin (tax equivalent) for the second quarter of 2017 was 4.12% , a decrease of 8 basis points from the linked quarter and an increase of 2 basis points from the prior year period. The decrease from the linked quarter was due to higher linked quarter interest income from taxable securities, which was driven by reduced amortization of premiums as well as lower incremental accretion in the current quarter. The increase from the prior year quarter was due to higher loan and security volumes, partially offset by lower incremental accretion. Columbia’s operating net interest margin (tax equivalent) ⁽¹⁾ was 4.09% for the second quarter of 2017 , unchanged from the linked quarter and an increase of 9 basis points from the prior year period due to higher loan and security volumes.

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 page of this earnings release for the reconciliation of operating net interest margin (tax equivalent) to net interest margin.

Asset Quality

At June 30, 2017 , nonperforming assets to total assets were 0.42% compared to 0.32% at March 31, 2017 and 0.35% at December 31, 2016 . Total nonperforming assets increased $10.8 million from the linked quarter due to an $11.3 million increase in nonaccrual loans, partially offset by a 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 both June 30, 2017 and March 31, 2017 . For the second quarter of 2017 , Columbia recorded a net provision for loan and lease losses of $3.2 million compared to a net provision of $2.8 million for the linked quarter and $3.6 million for the comparable quarter last year. The net provision for loan and lease losses recorded during the current quarter consisted of $3.9 million of provision for loan losses for loans, excluding PCI loans, partially offset by a provision recovery of $738 thousand for PCI loans.

Andy McDonald, Columbia’s Executive Vice President and Chief Credit Officer, commented, “Our nonperforming assets ratio of 42 basis points reflects the strength of our regional economy and the diversification within our loan portfolio.”

Organizational Update

Mr. Robbins commented, “Our pending acquisition of Pacific Continental Corporation is progressing. As announced last month, we have received the required shareholder approvals to complete the merger. Once the remaining regulatory approvals are obtained, we look forward to joining these two great companies together to the benefit of our customers, shareholders and the communities we serve. In addition, we regularly evaluate the alignment of our products and services with the needs of our clients. Given rapid technology changes in the payments industry, we are shifting our merchant card services business to an industry leading, third-party provider. We believe this transition will better serve our business clients via a broad selection of competitive, best-in-class payment processing solutions. This transaction will result in a one-time $14.0 million gain which will be recognized in the third quarter of 2017.”

Mr. Robbins continued, “I’m pleased to have recently announced some organization changes that are occurring at the Company. Clint Stein’s transition from Chief Financial Officer to Chief Operating Officer provides a great opportunity for leadership continuity as the two of us and our teams, have worked closely on the majority of our recently completed and in process strategic business initiatives. In addition to the national search for our next CFO, we have a search underway for an executive level Chief Risk Officer. This role will oversee the maturation of our existing enterprise risk management program and position us for future growth.”

Cash Dividend Announcement

Columbia will pay a regular cash dividend of $0.22 per common share on August 23, 2017 to shareholders of record as of the close of business on August 9, 2017.

Conference Call Information

Columbia’s management will discuss the second quarter 2017 results on a conference call scheduled for Thursday, July 27, 2017 at 1:00 p.m. Pacific Time (4:00 p.m. ET) . Interested parties join the live-streamed event and a replay of the event by using the site:

https://engage.vevent.com/rt/columbiabankingsystemincao~48444274

The conference call can also be accessed on Thursday, July 27, 2017 at 1:00 p.m. Pacific Time (4:00 p.m. ET) by calling 1-888-286-8956; Conference ID code #48444274.

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 eleventh consecutive year, the bank was named in 2017 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 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 has been 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 BECAUSE THEY CONTAIN IMPORTANT INFORMATION ABOUT 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.