﻿<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" returnVersion="2024v5.2" xsi:schemaLocation="http://www.irs.gov/efile">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2026-05-06T17:31:06-07:00</ReturnTs>
    <TaxPeriodEndDt>2025-06-30</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmEIN>260030246</PreparerFirmEIN>
      <PreparerFirmName>
        <BusinessNameLine1Txt>T CARMICHAEL PC</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>421 E UNIVERSITY DR</AddressLine1Txt>
        <CityNm>MESA</CityNm>
        <StateAbbreviationCd>AZ</StateAbbreviationCd>
        <ZIPCd>85203</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990</ReturnTypeCd>
    <TaxPeriodBeginDt>2024-07-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>237212637</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>MESA HISTORICAL SOCIETY INC</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>MESA</BusinessNameControlTxt>
      <PhoneNum>4808352286</PhoneNum>
      <USAddress>
        <AddressLine1Txt>2345 N HORNE</AddressLine1Txt>
        <CityNm>MESA</CityNm>
        <StateAbbreviationCd>AZ</StateAbbreviationCd>
        <ZIPCd>85203</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>SUSAN RICCI</PersonNm>
      <PersonTitleTxt>EXECUTIVE DIRECTOR</PersonTitleTxt>
      <PhoneNum>4808352286</PhoneNum>
      <SignatureDt>2026-04-30</SignatureDt>
      <DiscussWithPaidPreparerInd>true</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <IRSResponsiblePrtyInfoCurrInd>true</IRSResponsiblePrtyInfoCurrInd>
    <PreparerPersonGrp>
      <PreparerPersonNm>THERESA A CARMICHAEL</PreparerPersonNm>
      <PTIN>P00027374</PTIN>
      <PhoneNum>4806499550</PhoneNum>
      <PreparationDt>2026-05-06</PreparationDt>
    </PreparerPersonGrp>
    <TaxYr>2024</TaxYr>
    <BuildTS>2025-03-06 01:10:19Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="6">
    <IRS990 documentId="IRS990-01" referenceDocumentId="IRS990ScheduleO-01" softwareId="24020153">
      <DoingBusinessAsName>
        <BusinessNameLine1Txt>MESA HISTORICAL MUSEUM</BusinessNameLine1Txt>
      </DoingBusinessAsName>
      <PrincipalOfficerNm>ANITA PETERS</PrincipalOfficerNm>
      <USAddress>
        <AddressLine1Txt>PO BOX 582</AddressLine1Txt>
        <CityNm>MESA</CityNm>
        <StateAbbreviationCd>AZ</StateAbbreviationCd>
        <ZIPCd>85211</ZIPCd>
      </USAddress>
      <GrossReceiptsAmt>487327</GrossReceiptsAmt>
      <GroupReturnForAffiliatesInd>false</GroupReturnForAffiliatesInd>
      <Organization501c3Ind>X</Organization501c3Ind>
      <WebsiteAddressTxt>N/A</WebsiteAddressTxt>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <FormationYr>1966</FormationYr>
      <LegalDomicileStateCd>AZ</LegalDomicileStateCd>
      <ActivityOrMissionDesc>MESA HISTORICAL SOCIETY IS A PUBLIC MUSEUM DEDICATED TO PRESERVING MESAS RICH CULTURE AND HISTORY THROUGH COLLECTIONS AND EXHIBITS</ActivityOrMissionDesc>
      <VotingMembersGoverningBodyCnt>10</VotingMembersGoverningBodyCnt>
      <VotingMembersIndependentCnt>9</VotingMembersIndependentCnt>
      <TotalEmployeeCnt>4</TotalEmployeeCnt>
      <TotalVolunteersCnt>75</TotalVolunteersCnt>
      <TotalGrossUBIAmt>0</TotalGrossUBIAmt>
      <NetUnrelatedBusTxblIncmAmt>0</NetUnrelatedBusTxblIncmAmt>
      <PYContributionsGrantsAmt>306873</PYContributionsGrantsAmt>
      <CYContributionsGrantsAmt>343097</CYContributionsGrantsAmt>
      <PYProgramServiceRevenueAmt>14671</PYProgramServiceRevenueAmt>
      <CYProgramServiceRevenueAmt>10129</CYProgramServiceRevenueAmt>
      <PYInvestmentIncomeAmt>35182</PYInvestmentIncomeAmt>
      <CYInvestmentIncomeAmt>8250</CYInvestmentIncomeAmt>
      <PYOtherRevenueAmt>110937</PYOtherRevenueAmt>
      <CYOtherRevenueAmt>119212</CYOtherRevenueAmt>
      <PYTotalRevenueAmt>467663</PYTotalRevenueAmt>
      <CYTotalRevenueAmt>480688</CYTotalRevenueAmt>
      <CYGrantsAndSimilarPaidAmt>0</CYGrantsAndSimilarPaidAmt>
      <CYBenefitsPaidToMembersAmt>0</CYBenefitsPaidToMembersAmt>
      <PYSalariesCompEmpBnftPaidAmt>217497</PYSalariesCompEmpBnftPaidAmt>
      <CYSalariesCompEmpBnftPaidAmt>212953</CYSalariesCompEmpBnftPaidAmt>
      <PYTotalProfFndrsngExpnsAmt>4200</PYTotalProfFndrsngExpnsAmt>
      <CYTotalProfFndrsngExpnsAmt>0</CYTotalProfFndrsngExpnsAmt>
      <CYTotalFundraisingExpenseAmt>36503</CYTotalFundraisingExpenseAmt>
      <PYOtherExpensesAmt>103391</PYOtherExpensesAmt>
      <CYOtherExpensesAmt>109429</CYOtherExpensesAmt>
      <PYTotalExpensesAmt>325088</PYTotalExpensesAmt>
      <CYTotalExpensesAmt>322382</CYTotalExpensesAmt>
      <PYRevenuesLessExpensesAmt>142575</PYRevenuesLessExpensesAmt>
      <CYRevenuesLessExpensesAmt>158306</CYRevenuesLessExpensesAmt>
      <TotalAssetsBOYAmt>467508</TotalAssetsBOYAmt>
      <TotalAssetsEOYAmt>637230</TotalAssetsEOYAmt>
      <TotalLiabilitiesEOYAmt>0</TotalLiabilitiesEOYAmt>
      <NetAssetsOrFundBalancesBOYAmt>467508</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>637230</NetAssetsOrFundBalancesEOYAmt>
      <MissionDesc>MESA HISTORICAL SOCIETY IS A PUBLIC MUSEUM DEDICATED TO PRESERVING MESAS RICH CULTURE AND HISTORY THROUGH COLLECTIONS AND EXHIBITS</MissionDesc>
      <SignificantNewProgramSrvcInd>false</SignificantNewProgramSrvcInd>
      <SignificantChangeInd>false</SignificantChangeInd>
      <ExpenseAmt>180385</ExpenseAmt>
      <GrantAmt>0</GrantAmt>
      <RevenueAmt>13983</RevenueAmt>
      <Desc>MESA HISTORICAL SOCIETY FEATURES EXHIBITS DEDICATED TO THE CITY OF MESA, INCLUDING ITS PREHISTORIC BEGINNINGS WITH THE HOHOKAM TRIBE TO THE BIRTH OF THE EARLY PIONEER AGRICULTURE. THE MUSEUM PROGRAMS INCLUDE YEAR-ROUND EXHIBITS, HANDS-ON DEMONSTRATIONS, GROUP TOURS AND SPECIAL ROTATING EXHIBITS THROUGHOUT THE YEAR.</Desc>
      <TotalProgramServiceExpensesAmt>180385</TotalProgramServiceExpensesAmt>
      <DescribedInSection501c3Ind referenceDocumentId="IRS990ScheduleA-01" referenceDocumentName="IRS990ScheduleA">true</DescribedInSection501c3Ind>
      <ScheduleBRequiredInd referenceDocumentId="IRS990ScheduleB-01" referenceDocumentName="IRS990ScheduleB">true</ScheduleBRequiredInd>
      <PoliticalCampaignActyInd>false</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd>false</LobbyingActivitiesInd>
      <SubjectToProxyTaxInd>false</SubjectToProxyTaxInd>
      <DonorAdvisedFundInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</DonorAdvisedFundInd>
      <ConservationEasementsInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</ConservationEasementsInd>
      <CollectionsOfArtInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">true</CollectionsOfArtInd>
      <CreditCounselingInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</CreditCounselingInd>
      <DonorRstrOrQuasiEndowmentsInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</DonorRstrOrQuasiEndowmentsInd>
      <ReportLandBuildingEquipmentInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">true</ReportLandBuildingEquipmentInd>
      <ReportInvestmentsOtherSecInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</ReportInvestmentsOtherSecInd>
      <ReportProgramRelatedInvstInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</ReportProgramRelatedInvstInd>
      <ReportOtherAssetsInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</ReportOtherAssetsInd>
      <ReportOtherLiabilitiesInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</ReportOtherLiabilitiesInd>
      <IncludeFIN48FootnoteInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</IncludeFIN48FootnoteInd>
      <IndependentAuditFinclStmtInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</IndependentAuditFinclStmtInd>
      <ConsolidatedAuditFinclStmtInd referenceDocumentId="IRS990ScheduleD-01" referenceDocumentName="IRS990ScheduleD">false</ConsolidatedAuditFinclStmtInd>
      <SchoolOperatingInd>false</SchoolOperatingInd>
      <ForeignOfficeInd>false</ForeignOfficeInd>
      <ForeignActivitiesInd>false</ForeignActivitiesInd>
      <MoreThan5000KToOrgInd>false</MoreThan5000KToOrgInd>
      <MoreThan5000KToIndividualsInd>false</MoreThan5000KToIndividualsInd>
      <ProfessionalFundraisingInd referenceDocumentId="IRS990ScheduleG-01" referenceDocumentName="IRS990ScheduleG">false</ProfessionalFundraisingInd>
      <FundraisingActivitiesInd referenceDocumentId="IRS990ScheduleG-01" referenceDocumentName="IRS990ScheduleG">true</FundraisingActivitiesInd>
      <GamingActivitiesInd referenceDocumentId="IRS990ScheduleG-01" referenceDocumentName="IRS990ScheduleG">false</GamingActivitiesInd>
      <OperateHospitalInd>false</OperateHospitalInd>
      <GrantsToOrganizationsInd>false</GrantsToOrganizationsInd>
      <GrantsToIndividualsInd>false</GrantsToIndividualsInd>
      <ScheduleJRequiredInd>false</ScheduleJRequiredInd>
      <TaxExemptBondsInd>false</TaxExemptBondsInd>
      <EngagedInExcessBenefitTransInd>false</EngagedInExcessBenefitTransInd>
      <PYExcessBenefitTransInd>false</PYExcessBenefitTransInd>
      <LoanOutstandingInd>false</LoanOutstandingInd>
      <GrantToRelatedPersonInd>false</GrantToRelatedPersonInd>
      <BusinessRlnWithOrgMemInd>false</BusinessRlnWithOrgMemInd>
      <BusinessRlnWithFamMemInd>false</BusinessRlnWithFamMemInd>
      <BusinessRlnWith35CtrlEntInd>false</BusinessRlnWith35CtrlEntInd>
      <DeductibleNonCashContriInd>false</DeductibleNonCashContriInd>
      <DeductibleArtContributionInd>false</DeductibleArtContributionInd>
      <TerminateOperationsInd>false</TerminateOperationsInd>
      <PartialLiquidationInd>false</PartialLiquidationInd>
      <DisregardedEntityInd>false</DisregardedEntityInd>
      <RelatedEntityInd>false</RelatedEntityInd>
      <RelatedOrganizationCtrlEntInd>false</RelatedOrganizationCtrlEntInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>false</TrnsfrExmptNonChrtblRltdOrgInd>
      <ActivitiesConductedPrtshpInd>false</ActivitiesConductedPrtshpInd>
      <ScheduleORequiredInd>true</ScheduleORequiredInd>
      <IRPDocumentCnt>0</IRPDocumentCnt>
      <IRPDocumentW2GCnt>0</IRPDocumentW2GCnt>
      <EmployeeCnt>4</EmployeeCnt>
      <EmploymentTaxReturnsFiledInd>true</EmploymentTaxReturnsFiledInd>
      <UnrelatedBusIncmOverLimitInd>false</UnrelatedBusIncmOverLimitInd>
      <ForeignFinancialAccountInd>false</ForeignFinancialAccountInd>
      <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
      <TaxablePartyNotificationInd>false</TaxablePartyNotificationInd>
      <NondeductibleContributionsInd>false</NondeductibleContributionsInd>
      <QuidProQuoContributionsInd>false</QuidProQuoContributionsInd>
      <Form8282PropertyDisposedOfInd>false</Form8282PropertyDisposedOfInd>
      <RcvFndsToPayPrsnlBnftCntrctInd>false</RcvFndsToPayPrsnlBnftCntrctInd>
      <PayPremiumsPrsnlBnftCntrctInd>false</PayPremiumsPrsnlBnftCntrctInd>
      <IndoorTanningServicesInd>false</IndoorTanningServicesInd>
      <InfoInScheduleOPartVIInd>X</InfoInScheduleOPartVIInd>
      <GoverningBodyVotingMembersCnt>10</GoverningBodyVotingMembersCnt>
      <IndependentVotingMemberCnt>9</IndependentVotingMemberCnt>
      <FamilyOrBusinessRlnInd>false</FamilyOrBusinessRlnInd>
      <DelegationOfMgmtDutiesInd>false</DelegationOfMgmtDutiesInd>
      <ChangeToOrgDocumentsInd>false</ChangeToOrgDocumentsInd>
      <MaterialDiversionOrMisuseInd>false</MaterialDiversionOrMisuseInd>
      <MembersOrStockholdersInd>false</MembersOrStockholdersInd>
      <ElectionOfBoardMembersInd>false</ElectionOfBoardMembersInd>
      <DecisionsSubjectToApprovaInd>false</DecisionsSubjectToApprovaInd>
      <MinutesOfGoverningBodyInd>true</MinutesOfGoverningBodyInd>
      <MinutesOfCommitteesInd>true</MinutesOfCommitteesInd>
      <OfficerMailingAddressInd>false</OfficerMailingAddressInd>
      <LocalChaptersInd>false</LocalChaptersInd>
      <Form990ProvidedToGvrnBodyInd>true</Form990ProvidedToGvrnBodyInd>
      <ConflictOfInterestPolicyInd>true</ConflictOfInterestPolicyInd>
      <AnnualDisclosureCoveredPrsnInd>true</AnnualDisclosureCoveredPrsnInd>
      <RegularMonitoringEnfrcInd>true</RegularMonitoringEnfrcInd>
      <WhistleblowerPolicyInd>true</WhistleblowerPolicyInd>
      <DocumentRetentionPolicyInd>true</DocumentRetentionPolicyInd>
      <CompensationProcessCEOInd>true</CompensationProcessCEOInd>
      <CompensationProcessOtherInd>false</CompensationProcessOtherInd>
      <InvestmentInJointVentureInd>false</InvestmentInJointVentureInd>
      <UponRequestInd>X</UponRequestInd>
      <BooksInCareOfDetail>
        <PersonNm>ANITA PETERS</PersonNm>
        <PhoneNum>4808352286</PhoneNum>
        <USAddress>
          <AddressLine1Txt>PO BOX 582</AddressLine1Txt>
          <CityNm>MESA</CityNm>
          <StateAbbreviationCd>AZ</StateAbbreviationCd>
          <ZIPCd>85211</ZIPCd>
        </USAddress>
      </BooksInCareOfDetail>
      <Form990PartVIISectionAGrp>
        <PersonNm>CHARLES CRISMON</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>BOBBY FREEMAN</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>JEN VELEZ</PersonNm>
        <TitleTxt>TREASURER</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>GREG MAREK</PersonNm>
        <TitleTxt>PRESIDENT</TitleTxt>
        <AverageHoursPerWeekRt>3.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>KEN SHADLEY</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>SUSAN RICCI</PersonNm>
        <TitleTxt>EXECUTIVE DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>40.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>78333</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>BARB BINGHAM</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>ANDREW FRYE</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>SUSAN HAWKINS</PersonNm>
        <TitleTxt>VICE PRESIDENT</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>STEVE WOOD</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <TotalReportableCompFromOrgAmt>78333</TotalReportableCompFromOrgAmt>
      <TotReportableCompRltdOrgAmt>0</TotReportableCompRltdOrgAmt>
      <TotalOtherCompensationAmt>0</TotalOtherCompensationAmt>
      <FormerOfcrEmployeesListedInd>false</FormerOfcrEmployeesListedInd>
      <TotalCompGreaterThan150KInd>false</TotalCompGreaterThan150KInd>
      <CompensationFromOtherSrcsInd>false</CompensationFromOtherSrcsInd>
      <MembershipDuesAmt>5210</MembershipDuesAmt>
      <FundraisingAmt>15470</FundraisingAmt>
      <GovernmentGrantsAmt>125000</GovernmentGrantsAmt>
      <AllOtherContributionsAmt>197417</AllOtherContributionsAmt>
      <TotalContributionsAmt>343097</TotalContributionsAmt>
      <ProgramServiceRevenueGrp>
        <Desc>ADMISSIONS</Desc>
        <BusinessCd>900099</BusinessCd>
        <TotalRevenueColumnAmt>8877</TotalRevenueColumnAmt>
        <UnrelatedBusinessRevenueAmt>0</UnrelatedBusinessRevenueAmt>
        <ExclusionAmt>0</ExclusionAmt>
      </ProgramServiceRevenueGrp>
      <ProgramServiceRevenueGrp>
        <Desc>COLLECTION ROYALITIES/IMAGES</Desc>
        <BusinessCd>900099</BusinessCd>
        <TotalRevenueColumnAmt>1252</TotalRevenueColumnAmt>
        <UnrelatedBusinessRevenueAmt>0</UnrelatedBusinessRevenueAmt>
        <ExclusionAmt>0</ExclusionAmt>
      </ProgramServiceRevenueGrp>
      <TotalProgramServiceRevenueAmt>10129</TotalProgramServiceRevenueAmt>
      <InvestmentIncomeGrp>
        <TotalRevenueColumnAmt>2149</TotalRevenueColumnAmt>
        <UnrelatedBusinessRevenueAmt>0</UnrelatedBusinessRevenueAmt>
        <ExclusionAmt>2149</ExclusionAmt>
      </InvestmentIncomeGrp>
      <GrossRentsGrp>
        <RealAmt>80327</RealAmt>
      </GrossRentsGrp>
      <RentalIncomeOrLossGrp>
        <RealAmt>80327</RealAmt>
      </RentalIncomeOrLossGrp>
      <NetRentalIncomeOrLossGrp>
        <TotalRevenueColumnAmt>80327</TotalRevenueColumnAmt>
        <ExclusionAmt>80327</ExclusionAmt>
      </NetRentalIncomeOrLossGrp>
      <GrossAmountSalesAssetsGrp>
        <SecuritiesAmt>1338</SecuritiesAmt>
        <OtherAmt>4763</OtherAmt>
      </GrossAmountSalesAssetsGrp>
      <LessCostOthBasisSalesExpnssGrp>
        <SecuritiesAmt>0</SecuritiesAmt>
        <OtherAmt>0</OtherAmt>
      </LessCostOthBasisSalesExpnssGrp>
      <GainOrLossGrp>
        <SecuritiesAmt>1338</SecuritiesAmt>
        <OtherAmt>4763</OtherAmt>
      </GainOrLossGrp>
      <NetGainOrLossInvestmentsGrp>
        <TotalRevenueColumnAmt>6101</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>4763</RelatedOrExemptFuncIncomeAmt>
        <UnrelatedBusinessRevenueAmt>0</UnrelatedBusinessRevenueAmt>
        <ExclusionAmt>1338</ExclusionAmt>
      </NetGainOrLossInvestmentsGrp>
      <FundraisingGrossIncomeAmt>36882</FundraisingGrossIncomeAmt>
      <ContriRptFundraisingEventAmt>15470</ContriRptFundraisingEventAmt>
      <FundraisingDirectExpensesAmt>1851</FundraisingDirectExpensesAmt>
      <NetIncmFromFundraisingEvtGrp>
        <TotalRevenueColumnAmt>35031</TotalRevenueColumnAmt>
        <UnrelatedBusinessRevenueAmt>0</UnrelatedBusinessRevenueAmt>
        <ExclusionAmt>35031</ExclusionAmt>
      </NetIncmFromFundraisingEvtGrp>
      <GrossSalesOfInventoryAmt>8642</GrossSalesOfInventoryAmt>
      <CostOfGoodsSoldAmt>4788</CostOfGoodsSoldAmt>
      <NetIncomeOrLossGrp>
        <TotalRevenueColumnAmt>3854</TotalRevenueColumnAmt>
        <ExclusionAmt>3854</ExclusionAmt>
      </NetIncomeOrLossGrp>
      <TotalRevenueGrp>
        <TotalRevenueColumnAmt>480688</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>14892</RelatedOrExemptFuncIncomeAmt>
        <UnrelatedBusinessRevenueAmt>0</UnrelatedBusinessRevenueAmt>
        <ExclusionAmt>122699</ExclusionAmt>
      </TotalRevenueGrp>
      <CompCurrentOfcrDirectorsGrp>
        <TotalAmt>78333</TotalAmt>
        <ProgramServicesAmt>7133</ProgramServicesAmt>
        <ManagementAndGeneralAmt>42720</ManagementAndGeneralAmt>
        <FundraisingAmt>28480</FundraisingAmt>
      </CompCurrentOfcrDirectorsGrp>
      <OtherSalariesAndWagesGrp>
        <TotalAmt>87814</TotalAmt>
        <ProgramServicesAmt>82357</ProgramServicesAmt>
        <ManagementAndGeneralAmt>5457</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </OtherSalariesAndWagesGrp>
      <OtherEmployeeBenefitsGrp>
        <TotalAmt>34344</TotalAmt>
        <ProgramServicesAmt>18498</ProgramServicesAmt>
        <ManagementAndGeneralAmt>9959</ManagementAndGeneralAmt>
        <FundraisingAmt>5887</FundraisingAmt>
      </OtherEmployeeBenefitsGrp>
      <PayrollTaxesGrp>
        <TotalAmt>12462</TotalAmt>
        <ProgramServicesAmt>6712</ProgramServicesAmt>
        <ManagementAndGeneralAmt>3614</ManagementAndGeneralAmt>
        <FundraisingAmt>2136</FundraisingAmt>
      </PayrollTaxesGrp>
      <FeesForServicesAccountingGrp>
        <TotalAmt>2375</TotalAmt>
        <ProgramServicesAmt>0</ProgramServicesAmt>
        <ManagementAndGeneralAmt>2375</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </FeesForServicesAccountingGrp>
      <FeesForSrvcInvstMgmntFeesGrp>
        <TotalAmt>1211</TotalAmt>
        <ProgramServicesAmt>0</ProgramServicesAmt>
        <ManagementAndGeneralAmt>1211</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </FeesForSrvcInvstMgmntFeesGrp>
      <AdvertisingGrp>
        <TotalAmt>4578</TotalAmt>
        <ProgramServicesAmt>4353</ProgramServicesAmt>
        <ManagementAndGeneralAmt>225</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </AdvertisingGrp>
      <OfficeExpensesGrp>
        <TotalAmt>16023</TotalAmt>
        <ProgramServicesAmt>3727</ProgramServicesAmt>
        <ManagementAndGeneralAmt>12296</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </OfficeExpensesGrp>
      <InformationTechnologyGrp>
        <TotalAmt>2217</TotalAmt>
        <ProgramServicesAmt>2217</ProgramServicesAmt>
        <ManagementAndGeneralAmt>0</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </InformationTechnologyGrp>
      <OccupancyGrp>
        <TotalAmt>37559</TotalAmt>
        <ProgramServicesAmt>22536</ProgramServicesAmt>
        <ManagementAndGeneralAmt>15023</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </OccupancyGrp>
      <TravelGrp>
        <TotalAmt>529</TotalAmt>
        <ProgramServicesAmt>529</ProgramServicesAmt>
        <ManagementAndGeneralAmt>0</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </TravelGrp>
      <ConferencesMeetingsGrp>
        <TotalAmt>2513</TotalAmt>
        <ProgramServicesAmt>0</ProgramServicesAmt>
        <ManagementAndGeneralAmt>2513</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </ConferencesMeetingsGrp>
      <DepreciationDepletionGrp>
        <TotalAmt>6638</TotalAmt>
        <ProgramServicesAmt>3983</ProgramServicesAmt>
        <ManagementAndGeneralAmt>2655</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </DepreciationDepletionGrp>
      <InsuranceGrp>
        <TotalAmt>20553</TotalAmt>
        <ProgramServicesAmt>20234</ProgramServicesAmt>
        <ManagementAndGeneralAmt>319</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </InsuranceGrp>
      <OtherExpensesGrp>
        <Desc>DIGITIZATION</Desc>
        <TotalAmt>362</TotalAmt>
        <ProgramServicesAmt>362</ProgramServicesAmt>
        <ManagementAndGeneralAmt>0</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>MEMBERSHIP DUES</Desc>
        <TotalAmt>336</TotalAmt>
        <ProgramServicesAmt>0</ProgramServicesAmt>
        <ManagementAndGeneralAmt>336</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>SUPPLIES/SMALL EQP</Desc>
        <TotalAmt>11877</TotalAmt>
        <ProgramServicesAmt>5551</ProgramServicesAmt>
        <ManagementAndGeneralAmt>6326</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>MISC</Desc>
        <TotalAmt>2658</TotalAmt>
        <ProgramServicesAmt>2193</ProgramServicesAmt>
        <ManagementAndGeneralAmt>465</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
      </OtherExpensesGrp>
      <TotalFunctionalExpensesGrp>
        <TotalAmt>322382</TotalAmt>
        <ProgramServicesAmt>180385</ProgramServicesAmt>
        <ManagementAndGeneralAmt>105494</ManagementAndGeneralAmt>
        <FundraisingAmt>36503</FundraisingAmt>
      </TotalFunctionalExpensesGrp>
      <CashNonInterestBearingGrp>
        <BOYAmt>102598</BOYAmt>
        <EOYAmt>94071</EOYAmt>
      </CashNonInterestBearingGrp>
      <SavingsAndTempCashInvstGrp>
        <BOYAmt>95000</BOYAmt>
      </SavingsAndTempCashInvstGrp>
      <PrepaidExpensesDefrdChargesGrp>
        <BOYAmt>23713</BOYAmt>
        <EOYAmt>192305</EOYAmt>
      </PrepaidExpensesDefrdChargesGrp>
      <LandBldgEquipCostOrOtherBssAmt>260998</LandBldgEquipCostOrOtherBssAmt>
      <LandBldgEquipAccumDeprecAmt>14599</LandBldgEquipAccumDeprecAmt>
      <LandBldgEquipBasisNetGrp>
        <BOYAmt>246197</BOYAmt>
        <EOYAmt>246399</EOYAmt>
      </LandBldgEquipBasisNetGrp>
      <InvestmentsPubTradedSecGrp>
        <EOYAmt>104455</EOYAmt>
      </InvestmentsPubTradedSecGrp>
      <TotalAssetsGrp>
        <BOYAmt>467508</BOYAmt>
        <EOYAmt>637230</EOYAmt>
      </TotalAssetsGrp>
      <TotalLiabilitiesGrp>
        <BOYAmt>0</BOYAmt>
        <EOYAmt>0</EOYAmt>
      </TotalLiabilitiesGrp>
      <OrganizationFollowsFASB117Ind>X</OrganizationFollowsFASB117Ind>
      <NoDonorRestrictionNetAssetsGrp>
        <BOYAmt>371961</BOYAmt>
        <EOYAmt>532776</EOYAmt>
      </NoDonorRestrictionNetAssetsGrp>
      <DonorRestrictionNetAssetsGrp>
        <BOYAmt>95547</BOYAmt>
        <EOYAmt>104454</EOYAmt>
      </DonorRestrictionNetAssetsGrp>
      <TotalNetAssetsFundBalanceGrp>
        <BOYAmt>467508</BOYAmt>
        <EOYAmt>637230</EOYAmt>
      </TotalNetAssetsFundBalanceGrp>
      <TotLiabNetAssetsFundBalanceGrp>
        <BOYAmt>467508</BOYAmt>
        <EOYAmt>637230</EOYAmt>
      </TotLiabNetAssetsFundBalanceGrp>
      <ReconcilationRevenueExpnssAmt>158306</ReconcilationRevenueExpnssAmt>
      <NetUnrlzdGainsLossesInvstAmt>11416</NetUnrlzdGainsLossesInvstAmt>
      <MethodOfAccountingCashInd>X</MethodOfAccountingCashInd>
      <AccountantCompileOrReviewInd>false</AccountantCompileOrReviewInd>
      <FSAuditedInd>false</FSAuditedInd>
      <FederalGrantAuditRequiredInd>false</FederalGrantAuditRequiredInd>
    </IRS990>
    <IRS990ScheduleA documentId="IRS990ScheduleA-01" softwareId="24020153">
      <PublicOrganization170Ind>X</PublicOrganization170Ind>
      <OtherSupportSumAmt>0</OtherSupportSumAmt>
      <GiftsGrantsContriRcvd170Grp>
        <CurrentTaxYearMinus4YearsAmt>135880</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>149321</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>154123</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>306873</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>343097</CurrentTaxYearAmt>
        <TotalAmt>1089294</TotalAmt>
      </GiftsGrantsContriRcvd170Grp>
      <TaxRevLeviedOrgnztnlBnft170Grp>
        <TotalAmt>0</TotalAmt>
      </TaxRevLeviedOrgnztnlBnft170Grp>
      <GovtFurnSrvcFcltsVl170Grp>
        <TotalAmt>0</TotalAmt>
      </GovtFurnSrvcFcltsVl170Grp>
      <TotalCalendarYear170Grp>
        <CurrentTaxYearMinus4YearsAmt>135880</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>149321</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>154123</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>306873</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>343097</CurrentTaxYearAmt>
        <TotalAmt>1089294</TotalAmt>
      </TotalCalendarYear170Grp>
      <SubstantialContributorsTotAmt>18417</SubstantialContributorsTotAmt>
      <PublicSupportTotal170Amt>1070877</PublicSupportTotal170Amt>
      <GrossInvestmentIncome170Grp>
        <CurrentTaxYearMinus4YearsAmt>73781</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>73859</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>77780</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>79899</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>88577</CurrentTaxYearAmt>
        <TotalAmt>393896</TotalAmt>
      </GrossInvestmentIncome170Grp>
      <UnrelatedBusinessNetIncm170Grp>
        <TotalAmt>0</TotalAmt>
      </UnrelatedBusinessNetIncm170Grp>
      <OtherIncome170Grp>
        <CurrentTaxYearMinus4YearsAmt>9161</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>26499</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>22161</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>28123</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>35031</CurrentTaxYearAmt>
        <TotalAmt>120975</TotalAmt>
      </OtherIncome170Grp>
      <TotalSupportAmt>1604165</TotalSupportAmt>
      <PublicSupportCY170Pct>0.66760</PublicSupportCY170Pct>
      <PublicSupportPY170Pct>0.63200</PublicSupportPY170Pct>
      <ThirtyThrPctSuprtTestsCY170Ind>X</ThirtyThrPctSuprtTestsCY170Ind>
      <PublicSupportTotal509Amt>0</PublicSupportTotal509Amt>
      <PublicSupportCY509Pct>0</PublicSupportCY509Pct>
      <InvestmentIncomeCYPct>0</InvestmentIncomeCYPct>
      <Form990ScheduleAPartVIGrp>
        <FormAndLineReferenceDesc>Pt II Ln 10</FormAndLineReferenceDesc>
        <ExplanationTxt>Other Income Part II, Line 10 Description: FUNDRAISING 2020: 9161. 2021: 26499. 2022: 22161. 2023: 28123. 2024: 35031.</ExplanationTxt>
      </Form990ScheduleAPartVIGrp>
    </IRS990ScheduleA>
    <IRS990ScheduleB documentId="IRS990ScheduleB-01">
      <ContributorInformationGrp>
        <ContributorNum>RESTRICTED</ContributorNum>
        <ContributorBusinessName>
          <BusinessNameLine1>RESTRICTED</BusinessNameLine1>
        </ContributorBusinessName>
        <ContributorUSAddress>
          <AddressLine1>RESTRICTED</AddressLine1>
          <AddressLine2>RESTRICTED</AddressLine2>
          <City>RESTRICTED</City>
          <State>RESTRICTED</State>
          <ZIPCode>RESTRICTED</ZIPCode>
        </ContributorUSAddress>
        <TotalContributionsAmt>RESTRICTED</TotalContributionsAmt>
      </ContributorInformationGrp>
    </IRS990ScheduleB>
    <IRS990ScheduleD documentId="IRS990ScheduleD-01" softwareId="24020153">
      <CollectionUsedPubExhibitionInd>X</CollectionUsedPubExhibitionInd>
      <CollUsedScholarlyRsrchInd>X</CollUsedScholarlyRsrchInd>
      <CollectionUsedPreservationInd>X</CollectionUsedPreservationInd>
      <SolicitedAssetsSaleInd>false</SolicitedAssetsSaleInd>
      <BuildingsGrp>
        <InvestmentCostOrOtherBasisAmt>0</InvestmentCostOrOtherBasisAmt>
        <OtherCostOrOtherBasisAmt>260998</OtherCostOrOtherBasisAmt>
        <DepreciationAmt>14599</DepreciationAmt>
        <BookValueAmt>246399</BookValueAmt>
      </BuildingsGrp>
      <TotalBookValueLandBuildingsAmt>246399</TotalBookValueLandBuildingsAmt>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Pt III, Line 4</FormAndLineReferenceDesc>
        <ExplanationTxt>HISTORICAL COLLECTION AMASSED SINCE 1966 DEPICTING THE HISTORY OF MESA</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleD>
    <IRS990ScheduleG documentId="IRS990ScheduleG-01">
      <FundraisingEventInformationGrp>
        <Event1Nm>BOOK SALE</Event1Nm>
        <GrossReceiptsEvent1Amt>11865</GrossReceiptsEvent1Amt>
        <GrossRevenueEvent1Amt>11865</GrossRevenueEvent1Amt>
        <FoodAndBeverageEvent1Amt>147</FoodAndBeverageEvent1Amt>
        <OtherDirectExpensesEvent1Amt>350</OtherDirectExpensesEvent1Amt>
        <Event2Nm>HOME TOUR</Event2Nm>
        <GrossReceiptsEvent2Amt>11390</GrossReceiptsEvent2Amt>
        <GrossRevenueEvent2Amt>11390</GrossRevenueEvent2Amt>
        <OtherDirectExpensesEvent2Amt>154</OtherDirectExpensesEvent2Amt>
        <OtherEventsTotalCnt>5</OtherEventsTotalCnt>
        <GrossReceiptsOtherEventsAmt>13627</GrossReceiptsOtherEventsAmt>
        <GrossRevenueOtherEventsAmt>13627</GrossRevenueOtherEventsAmt>
        <FoodAndBeverageOtherEventsAmt>61</FoodAndBeverageOtherEventsAmt>
        <OthDirectExpnssOtherEventsAmt>1139</OthDirectExpnssOtherEventsAmt>
        <GrossReceiptsTotalAmt>36882</GrossReceiptsTotalAmt>
        <GrossRevenueTotalEventsAmt>36882</GrossRevenueTotalEventsAmt>
        <FoodAndBeverageTotalEventsAmt>208</FoodAndBeverageTotalEventsAmt>
        <OthDirectExpnssTotalEventsAmt>1643</OthDirectExpnssTotalEventsAmt>
        <DirectExpenseSummaryEventsAmt>1851</DirectExpenseSummaryEventsAmt>
        <NetIncomeSummaryAmt>35031</NetIncomeSummaryAmt>
      </FundraisingEventInformationGrp>
    </IRS990ScheduleG>
    <IRS990ScheduleO documentId="IRS990ScheduleO-01" softwareId="24020153">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Pt VI, Line 19</FormAndLineReferenceDesc>
        <ExplanationTxt>AVAILABLE UPON REQUEST</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Pt VI, Line 11b</FormAndLineReferenceDesc>
        <ExplanationTxt>THE RETURN IS CIRCULATED TO THE BOARD FOR REVIEW AND COMMENT PRIOR TO FILING.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Pt VI, Line 12c</FormAndLineReferenceDesc>
        <ExplanationTxt>BOARD MEMBERS COMPLETE A CONFLICT OF INTEREST FORM YEARLY.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Pt VI, Line 15a</FormAndLineReferenceDesc>
        <ExplanationTxt>EXECUTIVE DIRECTORS SALARY IS DETERMINED BASED ON COMPARISON TO OTHER DIRECTORS WITH SIMILAR CREDENTIALS FOR A COMPARABLE SIZED MUSEUM.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>