<SUBMISSION>
<ACCESSION-NUMBER>0000893538-05-000040
<TYPE>4/A
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20050315
<FILING-DATE>20050317
<DATE-OF-FILING-DATE-CHANGE>20050317
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>HELLERSTEIN MARK A
<CIK>0001198283
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4/A
<ACT>34
<FILE-NUMBER>001-31539
<FILM-NUMBER>05689943
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>1776 LINCOLN ST
<STREET2>STE 700
<CITY>DENVER
<STATE>CO
<ZIP>80202
</MAIL-ADDRESS>
</REPORTING-OWNER>
<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>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2005-03-15</periodOfReport>

    <dateOfOriginalSubmission>2005-03-17</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001198283</rptOwnerCik>
            <rptOwnerName>HELLERSTEIN MARK A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1776 LINCOLN ST</rptOwnerStreet1>
            <rptOwnerStreet2>STE 700</rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman, President &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-03-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3950</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>3950</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18678</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted unit repesents the contigent right to receive one share of SM common stock.</footnote>
        <footnote id="F2">The restricted stock units vest in four equal installments beginning March 15, 2005. Vested shares will be issued to the reporting person on March 15, 2008, at which time all restrictions lapse.</footnote>
        <footnote id="F3">This amendment is being filed because I put the wrong date &quot;3/15/2004&quot; in Item #3 on Page 1.  The date should be &quot;3/15/2005&quot;.  That is the only correction.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>James C. Robertson (Attorney-In-Fact)</signatureName>
        <signatureDate>2005-03-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
