<SUBMISSION>
<ACCESSION-NUMBER>0000893538-04-000081
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20040630
<FILING-DATE>20040701
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ST MARY LAND & EXPLORATION CO
<CIK>0000893538
<ASSIGNED-SIC>1311
<IRS-NUMBER>410518430
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>1776 LINCOLN ST STE 700
<CITY>DENVER
<STATE>CO
<ZIP>80203
<PHONE>303-861-8140
</BUSINESS-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>WILSON KEVIN E
<CIK>0001277437
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-31539
<FILM-NUMBER>04893894
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O ST MARY LAND & EXPLORATION
<STREET2>580 WESTLAKE PARK BLVD #600
<CITY>HOUSTON
<STATE>TX
<ZIP>77079
<PHONE>9184887600
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O ST MARY LAND & EXPLORATION
<STREET2>7060 S. YALE #800
<CITY>TULSA
<STATE>OK
<ZIP>74136
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-06-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000893538</issuerCik>
        <issuerName>ST MARY LAND &amp; EXPLORATION CO</issuerName>
        <issuerTradingSymbol>SM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001277437</rptOwnerCik>
            <rptOwnerName>WILSON KEVIN E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ST MARY LAND &amp; EXPLORATION</rptOwnerStreet1>
            <rptOwnerStreet2>7060 S. YALE #800</rptOwnerStreet2>
            <rptOwnerCity>TULSA</rptOwnerCity>
            <rptOwnerState>OK</rptOwnerState>
            <rptOwnerZipCode>74136</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-06-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8210</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock; $.01 Par Value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8210</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8210</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit represents a contingent right to receive one share of SM common stock.</footnote>
        <footnote id="F2">The restricted stock units vest in four equal annual installments beginning on June 30, 2004.  Vested shares will be issued to the reporting person on June 30, 2007, at which time all restrictions lapse.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>James C. Robertson (Attorney-In-Fact)</signatureName>
        <signatureDate>2004-06-30</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
