<SUBMISSION>
<ACCESSION-NUMBER>0000893538-05-000067
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20050526
<FILING-DATE>20050527
<DATE-OF-FILING-DATE-CHANGE>20050527
<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>GARDINER WILLIAM J
<CIK>0001198302
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-31539
<FILM-NUMBER>05862867
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>1776 LINCOLN ST
<STREET2>STE 700
<CITY>DENVER
<STATE>CO
<ZIP>80202
</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>2005-05-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001198302</rptOwnerCik>
            <rptOwnerName>GARDINER WILLIAM J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1776 LINCOLN ST</rptOwnerStreet1>
            <rptOwnerStreet2>STE 700</rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock; $.01 Par Value</value>
            </securityTitle>
            <transactionDate>
                <value>2005-05-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2321</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15321</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On May 26,2005 Mr. Gardiner was granted 2,321 shares of the issuer's common stock in lieu of directors fees.</footnote>
        <footnote id="F2">This total number of shares beneficially owned reflects the number of shares after the March 21,2005, two-for-one split effected by the issuer.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Brenda L. Schohn</signatureName>
        <signatureDate>2005-05-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
