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    <ACCEPTANCE-DATETIME>20220120175937
    ACCESSION NUMBER:		0000887343-22-000006
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		15
    CONFORMED PERIOD OF REPORT:	20220119
    ITEM INFORMATION:		Results of Operations and Financial Condition
    ITEM INFORMATION:		Other Events
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20220121
    DATE AS OF CHANGE:		20220120

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			COLUMBIA BANKING SYSTEM, INC.
    		CENTRAL INDEX KEY:			0000887343
    		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
    		IRS NUMBER:				911422237
    		STATE OF INCORPORATION:			WA
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-20288
    		FILM NUMBER:		22543402

    	BUSINESS ADDRESS:
    		STREET 1:		1301 A STREET
    		CITY:			TACOMA
    		STATE:			WA
    		ZIP:			98402
    		BUSINESS PHONE:		2533051900

    	MAIL ADDRESS:
    		STREET 1:		1301 A STREET
    		CITY:			TACOMA
    		STATE:			WA
    		ZIP:			98402

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	COLUMBIA BANKING SYSTEM INC
    		DATE OF NAME CHANGE:	19930328
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    <FILENAME>colb-20220119.htm
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    Document 1 - file: colb-20220119.htm

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    <FILENAME>a991colb4q2021earningsrele.htm
    <DESCRIPTION>PRESS RELEASE - EARNINGS AND DIVIDEND
    <TEXT>
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    <FILENAME>colb-20220119.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT
    <TEXT>
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    <FILENAME>colb-20220119_def.xml
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    <TYPE>EXCEL
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    <TEXT>
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    <FILENAME>report.css
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    <TEXT>
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    <SEQUENCE>13
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    <SEQUENCE>15
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