0001193125-07-170529 10-Q 4 20070630 20070803 20070803 COLUMBIA BANKING SYSTEM INC 0000887343 6022 911422237 WA 1231 10-Q 34 000-20288 071023605 1102 BROADWAY PLAZA TACOMA WA 98402 2533051900 1102 BROADWAY PLAZA TACOMA WA 98402 10-Q 1 d10q.htm FORM 10-Q EX-31.1 2 dex311.htm CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO SECTION 302 EX-31.2 3 dex312.htm CERTIFICATION OF CHIEF FINANCIAL OFFICER PURSUANT TO SECTION 302 EX-32 4 dex32.htm CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350