0001193125-07-111669 10-Q/A 4 20070331 20070511 20070511 COLUMBIA BANKING SYSTEM INC 0000887343 6022 911422237 WA 1231 10-Q/A 34 000-20288 07841977 1102 BROADWAY PLAZA TACOMA WA 98402 2533051900 1102 BROADWAY PLAZA TACOMA WA 98402 10-Q/A 1 d10qa.htm AMENDMENT NO. 1 TO FORM 10-Q EX-31.1 2 dex311.htm CERTIFICATION OF CHIEF EXECUTIVE OFFICER EX-31.2 3 dex312.htm CERTIFICATION OF CHIEF FINANCIAL OFFICER EX-32 4 dex32.htm SECTION 906 CERTIFICATION