0001193125-07-075549 425 3 20070405 20070405 MOUNTAIN BANK HOLDING CO 0000898018 6021 911602736 WA 1231 425 34 000-28394 07752469 501 ROOSEVELT AVE EAST PO BOX 98 ENUMCLAW WA 98022 2068250100 501 ROOSEVELE AVENUE ENUMCLAW WA 98022 COLUMBIA BANKING SYSTEM INC 0000887343 6022 911422237 WA 1231 425 1102 BROADWAY PLAZA TACOMA WA 98402 2533051900 1102 BROADWAY PLAZA TACOMA WA 98402 425 1 d8k.htm FORM 8-K EX-2.1 2 dex21.htm PLAN AND AGREEMENT OF MERGER EX-99.1 3 dex991.htm TRANSCRIPT OF MARCH 29, 2007 CONFERENCE CALL