﻿<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" returnVersion="2024v5.0">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2025-07-16T12:46:32-04:00</ReturnTs>
    <TaxPeriodEndDt>2024-12-31</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmEIN>871719185</PreparerFirmEIN>
      <PreparerFirmName>
        <BusinessNameLine1Txt>NEIDERHISER CONSULTING &amp; ACCOUNTING</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>2798 WOODGATE RD UNIT D</AddressLine1Txt>
        <CityNm>MONTROSE</CityNm>
        <StateAbbreviationCd>CO</StateAbbreviationCd>
        <ZIPCd>81401</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990EZ</ReturnTypeCd>
    <TaxPeriodBeginDt>2024-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>841176557</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>MONTROSE MARLINS INC</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>MONT</BusinessNameControlTxt>
      <PhoneNum>9702498611</PhoneNum>
      <USAddress>
        <AddressLine1Txt>PO BOX 1395</AddressLine1Txt>
        <CityNm>MONTROSE</CityNm>
        <StateAbbreviationCd>CO</StateAbbreviationCd>
        <ZIPCd>81402</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>JENNIFER JOHNSON</PersonNm>
      <PersonTitleTxt>PRESIDENT</PersonTitleTxt>
      <PhoneNum>9702498611</PhoneNum>
      <SignatureDt>2025-07-16</SignatureDt>
      <DiscussWithPaidPreparerInd>true</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <IRSResponsiblePrtyInfoCurrInd>true</IRSResponsiblePrtyInfoCurrInd>
    <PreparerPersonGrp>
      <PreparerPersonNm>CHRISTINE NEIDERHISER CPA</PreparerPersonNm>
      <PTIN>P01457025</PTIN>
      <PhoneNum>9705492327</PhoneNum>
      <PreparationDt>2025-07-16</PreparationDt>
    </PreparerPersonGrp>
    <TaxYr>2024</TaxYr>
    <BuildTS>2025-03-06 01:10:19Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="3">
    <IRS990EZ documentId="RetDoc2" referenceDocumentId="RetDoc3">
      <MethodOfAccountingAccrualInd>X</MethodOfAccountingAccrualInd>
      <ScheduleBNotRequiredInd>X</ScheduleBNotRequiredInd>
      <WebsiteAddressTxt>HTTP://WWW.MONTROSEMARLINS.ORG</WebsiteAddressTxt>
      <Organization501c3Ind referenceDocumentId="RetDoc4">X</Organization501c3Ind>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <GrossReceiptsAmt>93125</GrossReceiptsAmt>
      <InfoInScheduleOPartIInd>X</InfoInScheduleOPartIInd>
      <ContributionsGiftsGrantsEtcAmt>3000</ContributionsGiftsGrantsEtcAmt>
      <ProgramServiceRevenueAmt>35132</ProgramServiceRevenueAmt>
      <MembershipDuesAmt>54884</MembershipDuesAmt>
      <InvestmentIncomeAmt>109</InvestmentIncomeAmt>
      <TotalRevenueAmt>93125</TotalRevenueAmt>
      <SalariesOtherCompEmplBnftAmt>37186</SalariesOtherCompEmplBnftAmt>
      <FeesAndOtherPymtToIndCntrctAmt>7632</FeesAndOtherPymtToIndCntrctAmt>
      <OtherExpensesTotalAmt>47610</OtherExpensesTotalAmt>
      <TotalExpensesAmt>92428</TotalExpensesAmt>
      <ExcessOrDeficitForYearAmt>697</ExcessOrDeficitForYearAmt>
      <NetAssetsOrFundBalancesBOYAmt>65808</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>66505</NetAssetsOrFundBalancesEOYAmt>
      <InfoInScheduleOPartIIInd>X</InfoInScheduleOPartIIInd>
      <CashSavingsAndInvestmentsGrp>
        <BOYAmt>59499</BOYAmt>
        <EOYAmt>66122</EOYAmt>
      </CashSavingsAndInvestmentsGrp>
      <OtherAssetsTotalDetail>
        <BOYAmt>6541</BOYAmt>
        <EOYAmt>383</EOYAmt>
      </OtherAssetsTotalDetail>
      <Form990TotalAssetsGrp>
        <BOYAmt>66040</BOYAmt>
        <EOYAmt>66505</EOYAmt>
      </Form990TotalAssetsGrp>
      <SumOfTotalLiabilitiesGrp>
        <BOYAmt>232</BOYAmt>
      </SumOfTotalLiabilitiesGrp>
      <NetAssetsOrFundBalancesGrp>
        <BOYAmt>65808</BOYAmt>
        <EOYAmt>66505</EOYAmt>
      </NetAssetsOrFundBalancesGrp>
      <PrimaryExemptPurposeTxt>SWIM TEAM</PrimaryExemptPurposeTxt>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>PROMOTE THE SWIM TEAM EXPERIENCE THROUGH ALL AGES AND SKILL LEVELS</DescriptionProgramSrvcAccomTxt>
        <ProgramServiceExpensesAmt>92428</ProgramServiceExpensesAmt>
      </ProgramSrvcAccomplishmentGrp>
      <TotalProgramServiceExpensesAmt>92428</TotalProgramServiceExpensesAmt>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>JENNIFER JOHNSON</PersonNm>
        <TitleTxt>PRESIDENT</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>2.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>THANE STRANATHAN</PersonNm>
        <TitleTxt>VICE PRESIDE</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>JENNIFER REHARD</PersonNm>
        <TitleTxt>ADMIN OFFICA</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>2.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>VENUS CARIAZO</PersonNm>
        <TitleTxt>FUNDRAISER M</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>AARON CLUBB</PersonNm>
        <TitleTxt>TREASURER</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>4.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>BETH COURTER</PersonNm>
        <TitleTxt>SECRETARY</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>SKYLAR JOSEPH</PersonNm>
        <TitleTxt>CONCESSION M</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <ActivitiesNotPreviouslyRptInd>false</ActivitiesNotPreviouslyRptInd>
      <ChgMadeToOrgnzngDocNotRptInd>false</ChgMadeToOrgnzngDocNotRptInd>
      <OrganizationHadUBIInd>false</OrganizationHadUBIInd>
      <SubjectToProxyTaxInd>false</SubjectToProxyTaxInd>
      <OrganizationDissolvedEtcInd>false</OrganizationDissolvedEtcInd>
      <Form1120PolFiledInd>false</Form1120PolFiledInd>
      <MadeLoansToFromOfficersInd>false</MadeLoansToFromOfficersInd>
      <EngagedInExcessBenefitTransInd>false</EngagedInExcessBenefitTransInd>
      <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
      <BooksInCareOfDetail>
        <PersonNm>JENNIFER JOHNSON</PersonNm>
        <USAddress>
          <AddressLine1Txt>PO BOX 1395</AddressLine1Txt>
          <CityNm>MONTROSE</CityNm>
          <StateAbbreviationCd>CO</StateAbbreviationCd>
          <ZIPCd>81402</ZIPCd>
        </USAddress>
        <PhoneNum>9702498611</PhoneNum>
      </BooksInCareOfDetail>
      <ForeignFinancialAccountInd>false</ForeignFinancialAccountInd>
      <ForeignOfficeInd>false</ForeignOfficeInd>
      <DonorAdvisedFndsInd>false</DonorAdvisedFndsInd>
      <OperateHospitalInd>false</OperateHospitalInd>
      <TanningServicesProvidedInd>false</TanningServicesProvidedInd>
      <RelatedOrganizationCtrlEntInd>false</RelatedOrganizationCtrlEntInd>
      <TransactionWithControlEntInd>false</TransactionWithControlEntInd>
      <PoliticalCampaignActyInd>false</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd>false</LobbyingActivitiesInd>
      <SchoolOperatingInd>false</SchoolOperatingInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>false</TrnsfrExmptNonChrtblRltdOrgInd>
      <PartVIOfCompOfHghstPdEmplTxt>NONE</PartVIOfCompOfHghstPdEmplTxt>
      <PartVIHghstPdCntrctProfSrvcTxt>NONE</PartVIHghstPdCntrctProfSrvcTxt>
      <FiledScheduleAInd>true</FiledScheduleAInd>
    </IRS990EZ>
    <IRS990ScheduleA documentId="RetDoc4">
      <PubliclySupportedOrg509a2Ind>X</PubliclySupportedOrg509a2Ind>
      <GiftsGrantsContrisRcvd509Grp>
        <CurrentTaxYearMinus4YearsAmt>33188</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>39802</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>54736</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>56518</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>54884</CurrentTaxYearAmt>
        <TotalAmt>239128</TotalAmt>
      </GiftsGrantsContrisRcvd509Grp>
      <GrossReceiptsAdmissionsGrp>
        <CurrentTaxYearMinus4YearsAmt>39747</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>3261</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>12889</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>27792</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>35132</CurrentTaxYearAmt>
        <TotalAmt>118821</TotalAmt>
      </GrossReceiptsAdmissionsGrp>
      <Total509Grp>
        <CurrentTaxYearMinus4YearsAmt>72935</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>43063</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>67625</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>84310</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>90016</CurrentTaxYearAmt>
        <TotalAmt>357949</TotalAmt>
      </Total509Grp>
      <PublicSupportTotal509Amt>357949</PublicSupportTotal509Amt>
      <GrossInvestmentIncome509Grp>
        <CurrentTaxYearMinus4YearsAmt>5</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>2</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>8</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>97</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>109</CurrentTaxYearAmt>
        <TotalAmt>221</TotalAmt>
      </GrossInvestmentIncome509Grp>
      <InvestmentIncomeAndUBTIGrp>
        <CurrentTaxYearMinus4YearsAmt>5</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>2</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>8</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>97</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>109</CurrentTaxYearAmt>
        <TotalAmt>221</TotalAmt>
      </InvestmentIncomeAndUBTIGrp>
      <OtherIncome509Grp>
        <CurrentTaxYearMinus3YearsAmt>242</CurrentTaxYearMinus3YearsAmt>
        <TotalAmt>242</TotalAmt>
      </OtherIncome509Grp>
      <TotalSupportCalendarYearGrp>
        <CurrentTaxYearMinus4YearsAmt>72940</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>43307</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>67633</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>84407</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>90125</CurrentTaxYearAmt>
        <TotalAmt>358412</TotalAmt>
      </TotalSupportCalendarYearGrp>
      <PublicSupportCY509Pct>0.99870</PublicSupportCY509Pct>
      <PublicSupportPY509Pct>0.99890</PublicSupportPY509Pct>
      <InvestmentIncomeCYPct>0.00000</InvestmentIncomeCYPct>
      <InvestmentIncomePYPct>0.00000</InvestmentIncomePYPct>
      <ThirtyThrPctSuprtTestsCY509Ind>X</ThirtyThrPctSuprtTestsCY509Ind>
      <Form990ScheduleAPartVIGrp>
        <FormAndLineReferenceDesc>PART III, LINE 12</FormAndLineReferenceDesc>
        <ExplanationTxt>OTHER INCOME 242</ExplanationTxt>
      </Form990ScheduleAPartVIGrp>
    </IRS990ScheduleA>
    <IRS990ScheduleO documentId="RetDoc3">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990-EZ, PART I, LINE 16</FormAndLineReferenceDesc>
        <ExplanationTxt>EXPENSES ADVERTISING 2,688 OFFICE 3,250 WORKERS COMP 321 DUES &amp; SUBSCRIPTIONS 6,663 MEALS 2,777 SWIM MEET EXPENSES 16,380 CONCESSIONS 1,147 REIMBURSEMENTS 7,950 REPAIRS 61 SUPPLIES 702 GIFTS 250 EQUIPMENT RENTAL 119 CSI REGISTRATION &amp; FEES 4,973 NON-INVESTMENT DEPRECIATION 329 TOTAL 47,610</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990-EZ, PART II, LINE 24</FormAndLineReferenceDesc>
        <ExplanationTxt>PREPAID EXPENSES AND DEFERRED CHARGES 5,829 0 40,688 40,688 LESS ACCUMULATED DEPRECIATION 39,976 40,305 TOTAL 6,541 383</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990-EZ, PART II, LINE 26</FormAndLineReferenceDesc>
        <ExplanationTxt>OTHER LIABILITIES 232 0</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>