﻿<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.irs.gov/efile" returnVersion="2025v4.1">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2026-09-03T01:05:28-00:00</ReturnTs>
    <TaxPeriodEndDt>2025-12-31</TaxPeriodEndDt>
    <ReturnTypeCd>990EZ</ReturnTypeCd>
    <TaxPeriodBeginDt>2025-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>843176642</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>THAYER CONSERVATION FOUNDATION INC</BusinessNameLine1Txt>
      </BusinessName>
      <InCareOfNm>% W HADER INC</InCareOfNm>
      <BusinessNameControlTxt>THAY</BusinessNameControlTxt>
      <USAddress>
        <AddressLine1Txt>30 N GOULD ST STE 5906</AddressLine1Txt>
        <CityNm>SHERIDAN</CityNm>
        <StateAbbreviationCd>WY</StateAbbreviationCd>
        <ZIPCd>82801</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>ROBERT WOLFE</PersonNm>
      <PersonTitleTxt>CHAIRMAN CEO</PersonTitleTxt>
      <SignatureDt>2026-08-15</SignatureDt>
      <DiscussWithPaidPreparerInd>false</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <TaxYr>2025</TaxYr>
  </ReturnHeader>
  <ReturnData documentCnt="4">
    <IRS990EZ documentId="990EZ" softwareId="25022281" softwareVersionNum="25.0.1.0">
      <MethodOfAccountingAccrualInd>X</MethodOfAccountingAccrualInd>
      <ScheduleBNotRequiredInd>X</ScheduleBNotRequiredInd>
      <WebsiteAddressTxt>N/A</WebsiteAddressTxt>
      <Organization501c3Ind referenceDocumentId="990A">X</Organization501c3Ind>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <InfoInScheduleOPartIInd>X</InfoInScheduleOPartIInd>
      <OtherExpensesTotalAmt>360</OtherExpensesTotalAmt>
      <TotalExpensesAmt>360</TotalExpensesAmt>
      <ExcessOrDeficitForYearAmt>-360</ExcessOrDeficitForYearAmt>
      <NetAssetsOrFundBalancesBOYAmt>-19029</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>-19389</NetAssetsOrFundBalancesEOYAmt>
      <InfoInScheduleOPartIIInd>X</InfoInScheduleOPartIIInd>
      <Form990TotalAssetsGrp>
        <BOYAmt>0</BOYAmt>
        <EOYAmt>0</EOYAmt>
      </Form990TotalAssetsGrp>
      <SumOfTotalLiabilitiesGrp>
        <BOYAmt>19029</BOYAmt>
        <EOYAmt>19389</EOYAmt>
      </SumOfTotalLiabilitiesGrp>
      <NetAssetsOrFundBalancesGrp>
        <BOYAmt>-19029</BOYAmt>
        <EOYAmt>-19389</EOYAmt>
      </NetAssetsOrFundBalancesGrp>
      <PrimaryExemptPurposeTxt>CONSERVATION</PrimaryExemptPurposeTxt>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>CONSERVATION ATTEMPTS</DescriptionProgramSrvcAccomTxt>
      </ProgramSrvcAccomplishmentGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>DIRECTOR</PersonNm>
        <TitleTxt>CHAIRMAN CEO</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>010.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>JEFFERY BARKER</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>010.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>LAWRENCE DONDOFRIO</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>001.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <ActivitiesNotPreviouslyRptInd>false</ActivitiesNotPreviouslyRptInd>
      <ChgMadeToOrgnzngDocNotRptInd>false</ChgMadeToOrgnzngDocNotRptInd>
      <OrganizationHadUBIInd>false</OrganizationHadUBIInd>
      <SubjectToProxyTaxInd>false</SubjectToProxyTaxInd>
      <OrganizationDissolvedEtcInd>false</OrganizationDissolvedEtcInd>
      <Form1120PolFiledInd>false</Form1120PolFiledInd>
      <MadeLoansToFromOfficersInd>true</MadeLoansToFromOfficersInd>
      <LoansToFromOfficersAmt referenceDocumentId="990L">19029</LoansToFromOfficersAmt>
      <TaxImposedUnderIRC4911Amt>0</TaxImposedUnderIRC4911Amt>
      <TaxImposedUnderIRC4912Amt>0</TaxImposedUnderIRC4912Amt>
      <TaxImposedUnderIRC4955Amt>0</TaxImposedUnderIRC4955Amt>
      <EngagedInExcessBenefitTransInd>false</EngagedInExcessBenefitTransInd>
      <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
      <BooksInCareOfDetail>
        <BusinessName>
          <BusinessNameLine1Txt>THAYER CONSERVATION FOUNDATIOIN INC</BusinessNameLine1Txt>
        </BusinessName>
        <USAddress>
          <AddressLine1Txt>30 N GOULD ST ST 5906</AddressLine1Txt>
          <CityNm>SHERIDAN</CityNm>
          <StateAbbreviationCd>WY</StateAbbreviationCd>
          <ZIPCd>82801</ZIPCd>
        </USAddress>
        <PhoneNum>8023326100</PhoneNum>
      </BooksInCareOfDetail>
      <ForeignFinancialAccountInd>false</ForeignFinancialAccountInd>
      <ForeignOfficeInd>false</ForeignOfficeInd>
      <DonorAdvisedFndsInd>false</DonorAdvisedFndsInd>
      <OperateHospitalInd>false</OperateHospitalInd>
      <TanningServicesProvidedInd>false</TanningServicesProvidedInd>
      <Form720FiledInd>false</Form720FiledInd>
      <RelatedOrganizationCtrlEntInd>false</RelatedOrganizationCtrlEntInd>
      <TransactionWithControlEntInd>false</TransactionWithControlEntInd>
      <PoliticalCampaignActyInd>false</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd>false</LobbyingActivitiesInd>
      <SchoolOperatingInd>false</SchoolOperatingInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>false</TrnsfrExmptNonChrtblRltdOrgInd>
      <RelatedOrgSect527OrgInd>false</RelatedOrgSect527OrgInd>
      <PartVIOfCompOfHghstPdEmplTxt>NONE</PartVIOfCompOfHghstPdEmplTxt>
      <PartVIHghstPdCntrctProfSrvcTxt>NONE</PartVIHghstPdCntrctProfSrvcTxt>
      <FiledScheduleAInd>true</FiledScheduleAInd>
    </IRS990EZ>
    <IRS990ScheduleA documentId="990A" softwareId="25022281" softwareVersionNum="25.0.1.0">
      <PublicOrganization170Ind>X</PublicOrganization170Ind>
      <PublicSupportTotal170Amt>0</PublicSupportTotal170Amt>
      <PublicSupportCY170Pct>0.00000</PublicSupportCY170Pct>
      <PrivateFoundation170Ind>X</PrivateFoundation170Ind>
      <PrivateFoundation509Ind>X</PrivateFoundation509Ind>
    </IRS990ScheduleA>
    <IRS990ScheduleL documentId="990L" softwareId="25022281" softwareVersionNum="25.0.1.0">
      <LoansBtwnOrgInterestedPrsnGrp>
        <PersonNm>ROBERT WOLFE</PersonNm>
        <RelationshipWithOrgTxt>CHAIRMAN</RelationshipWithOrgTxt>
        <LoanPurposeTxt>PAY OPERATING EXPENSES</LoanPurposeTxt>
        <LoanToOrganizationInd>X</LoanToOrganizationInd>
        <OriginalPrincipalAmt>19029</OriginalPrincipalAmt>
        <BalanceDueAmt>19029</BalanceDueAmt>
      </LoansBtwnOrgInterestedPrsnGrp>
      <TotalBalanceDueAmt>19029</TotalBalanceDueAmt>
    </IRS990ScheduleL>
    <IRS990ScheduleO documentId="990O" softwareId="25022281" softwareVersionNum="25.0.1.0">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990-EZ, Part I, Line 16, Other Expenses</FormAndLineReferenceDesc>
        <ExplanationTxt>Bank Fees 360</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990-EZ, Part II, Line 26, Liabilities</FormAndLineReferenceDesc>
        <ExplanationTxt>TOTAL LIABILITIES Beginning of year 19,029, End of year 19,389</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>