-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 CWASbz5fjA8B9iW57w4e03tVf/t5POGku9xPoMl6qMIH75E/OqQ4WklAQjlfFoNc
 lNFGlGFXwOvZ9YgBI2DfYA==

<SEC-DOCUMENT>0001140361-08-018212.txt : 20080805
<SEC-HEADER>0001140361-08-018212.hdr.sgml : 20080805
<ACCEPTANCE-DATETIME>20080805104439
ACCESSION NUMBER:		0001140361-08-018212
CONFORMED SUBMISSION TYPE:	3/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080702
FILED AS OF DATE:		20080805
DATE AS OF CHANGE:		20080805

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ST MARY LAND & EXPLORATION CO
		CENTRAL INDEX KEY:			0000893538
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				410518430
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1776 LINCOLN ST STE 700
		CITY:			DENVER
		STATE:			CO
		ZIP:			80203
		BUSINESS PHONE:		303-861-8140

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Monark John R
		CENTRAL INDEX KEY:			0001437700

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31539
		FILM NUMBER:		08990055

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(303) 861-8140

	MAIL ADDRESS:	
		STREET 1:		1776 LINCOLN STREET
		STREET 2:		SUITE 700
		CITY:			DENVER
		STATE:			CO
		ZIP:			80203
</SEC-HEADER>
<DOCUMENT>
<TYPE>3/A
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 3/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2008-07-02</periodOfReport>

    <dateOfOriginalSubmission>2008-07-02</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001437700</rptOwnerCik>
            <rptOwnerName>Monark John R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1776 LINCOLN STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 700</rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP - Human Resources</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>543</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit represents a contingent right to receive one share of stock.  This restricted stock unit grant vests in three equal annual installments beginning on December 15, 2008.  The vested shares will be issued to the reporting person on the vesting dates, at which time all restrictions on the vested shares will lapse.</footnote>
        <footnote id="F2">The sole purpose of this amendment is to correct the number of shares with respect to the derivative securities beneficially owned.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Karin M. Writer (Attorney-In-Fact)</signatureName>
        <signatureDate>2008-08-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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