Exhibit 23.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement on Form S-8 of our reports relating to the consolidated financial statements of Columbia Banking System, Inc. and management’s report on the effectiveness of internal control over financial reporting dated March 1, 2007, appearing in the Annual Report on Form 10-K of Columbia Banking System, Inc. for the year ended December 31, 2006.

/s/ Deloitte & Touche LLP

Seattle, Washington

July 24, 2007