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  <xs:element id="colb_CounterpartyDefaultLossOnForwardContract" abstract="false" name="CounterpartyDefaultLossOnForwardContract" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_InterestRateFuturesContractsMember" abstract="true" name="InterestRateFuturesContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="colb_MortgageBackedSecurityMember" abstract="true" name="MortgageBackedSecurityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="colb_DerivativeAssetsGrossAmountsOffsettingTheBalanceSheets" abstract="false" name="DerivativeAssetsGrossAmountsOffsettingTheBalanceSheets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_DerivativeLiabilityGrossAmountsOffsetInBalanceSheets" abstract="false" name="DerivativeLiabilityGrossAmountsOffsetInBalanceSheets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_EarningsPerCommonShareAbstract" abstract="true" name="EarningsPerCommonShareAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="colb_October2025ShareRepurchaseProgramMember" abstract="true" name="October2025ShareRepurchaseProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="colb_EquityAndOtherInvestmentSecuritiesExcludingInvestmentsMeasuredAtNetAssetValuePerShare" abstract="false" name="EquityAndOtherInvestmentSecuritiesExcludingInvestmentsMeasuredAtNetAssetValuePerShare" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_EquityAndOtherInvestmentSecuritiesMeasuredAtNetAssetValuePerShare" abstract="false" name="EquityAndOtherInvestmentSecuritiesMeasuredAtNetAssetValuePerShare" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_HeldForSaleAndTransferredIntoLoansHeldForInvestment" abstract="false" name="HeldForSaleAndTransferredIntoLoansHeldForInvestment" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_InvestmentsInMutualFundsAndOtherEquitySecuritiesMember" abstract="true" name="InvestmentsInMutualFundsAndOtherEquitySecuritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="colb_EquitySecuritiesRabbiTrustMember" abstract="true" name="EquitySecuritiesRabbiTrustMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="colb_FeesAndCommissionsMortgageBankingAndServicingMember" abstract="true" name="FeesAndCommissionsMortgageBankingAndServicingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="colb_MortgageServicingRightsMember" abstract="true" name="MortgageServicingRightsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="colb_JuniorSubordinatedDebenturesMember" abstract="true" name="JuniorSubordinatedDebenturesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="colb_ChangeInUnrealizedGainsOrLossesForThePeriodIncludedInOtherComprehensiveIncomeForAssetsHeldAtEndOfPeriod" abstract="false" name="ChangeInUnrealizedGainsOrLossesForThePeriodIncludedInOtherComprehensiveIncomeForAssetsHeldAtEndOfPeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesAndIssuances" abstract="false" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesAndIssuances" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSalesAndSettlements" abstract="false" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSalesAndSettlements" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesAndIssuances" abstract="false" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesAndIssuances" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySalesAndSettlements" abstract="false" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySalesAndSettlements" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_LoansAndLeasesMember" abstract="true" name="LoansAndLeasesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="colb_LossMeasuredAtFairValueOnNonrecurringBasis" abstract="false" name="LossMeasuredAtFairValueOnNonrecurringBasis" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_FairValueOptionAggregateUnpaidBalanceLoansAndLongTermReceivables" abstract="false" name="FairValueOptionAggregateUnpaidBalanceLoansAndLongTermReceivables" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_FairValueLoansHeldAsAssetsAggregateUnpaidBalanceLoansAndLongTermReceivables" abstract="false" name="FairValueLoansHeldAsAssetsAggregateUnpaidBalanceLoansAndLongTermReceivables" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="colb_EffectiveTaxRateAsAPercentageOfPreTaxIncomeLoss" abstract="false" name="EffectiveTaxRateAsAPercentageOfPreTaxIncomeLoss" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="colb_TorranNixonMember" abstract="true" name="TorranNixonMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
