<SUBMISSION>
<ACCESSION-NUMBER>0001104659-07-088747
<TYPE>424B7
<PUBLIC-DOCUMENT-COUNT>1
<FILING-DATE>20071213
<DATE-OF-FILING-DATE-CHANGE>20071213
<FILER>
<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>
<FILING-VALUES>
<FORM-TYPE>424B7
<ACT>33
<FILE-NUMBER>333-143815
<FILM-NUMBER>071305126
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>1776 LINCOLN ST STE 700
<CITY>DENVER
<STATE>CO
<ZIP>80203
<PHONE>303-861-8140
</BUSINESS-ADDRESS>
</FILER>
<DOCUMENT>
<TYPE>424B7
<SEQUENCE>1
<FILENAME>a07-31410_1424b7.htm
<DESCRIPTION>424B7
<TEXT>

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<table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
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  <p style="color:windowtext;margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">PROSPECTUS
  SUPPLEMENT NO. 4</font></b></p>
  </td>
  <td width="5%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:5.52%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
  </td>
  <td width="42%" valign="top" style="padding:0in .7pt 0in .7pt;width:42.02%;">
  <p align="right" style="color:windowtext;margin:0in 0in .0001pt;text-align:right;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Filed Pursuant to Rule&nbsp;424(b)(7)</font></p>
  </td>
 </tr>
 <tr>
  <td width="52%" valign="top" style="padding:0in .7pt 0in .7pt;width:52.44%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">(To Prospectus Dated June&nbsp;15, 2007)</font></b></p>
  </td>
  <td width="5%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:5.52%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
  </td>
  <td width="42%" valign="top" style="padding:0in .7pt 0in .7pt;width:42.02%;">
  <p align="right" style="color:windowtext;margin:0in 0in .0001pt;text-align:right;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Registration
  No.&nbsp;333-143815</font></p>
  </td>
 </tr>
</table>

<p style="color:windowtext;margin:0in 0in .0001pt;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">$287,500,000</font></b></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">St. Mary Land&nbsp;&amp; Exploration Company</font></b></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">3.50%
Senior Convertible Notes due 2027</font></b></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">and
Common Stock Issuable Upon Conversion of 3.50%</font></b></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Senior
Convertible Notes due 2027</font></b></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">This prospectus supplement no. 4 supplements and amends our prospectus
dated June&nbsp;15, 2007, as amended and supplemented by prospectus supplement
no. 1 dated July&nbsp;20, 2007, prospectus supplement no. 2 dated August&nbsp;21,
2007 and prospectus supplement no. 3 dated November&nbsp;9, 2007 (collectively,
the &#147;Prospectus&#148;), relating to the resale from time to time by certain selling
securityholders of up to $287,500,000 principal amount of the notes and the
shares of common stock issuable upon conversion of the notes.</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">This prospectus supplement no. 4 should be read in conjunction with and
accompanied by the Prospectus and is qualified by reference to the Prospectus,
except to the extent that the information in this prospectus supplement no. 4
supersedes the information contained in the Prospectus.</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">The information appearing in the table below, which is based on
information provided by or on behalf of the named selling securityholder,
supplements and amends, by addition or substitution, as applicable, the
information in the table appearing under the heading &#147;Selling Securityholders&#148;
in the Prospectus.&#160; The percentage of
notes outstanding beneficially owned by each selling securityholder is based on
$287,500,000 aggregate initial principal amount of notes outstanding.</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.02%;">
 <tr>
  <td width="38%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:38.94%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;"><br>
  Name</font></b></p>
  </td>
  <td width="1%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:1.36%;">
  <p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
  </td>
  <td width="13%" colspan="2" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:13.56%;">
  <p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Aggregate Principal Amount of Notes That May&nbsp;Be Sold</font></b></p>
  </td>
  <td width="1%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:1.36%;">
  <p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
  </td>
  <td width="13%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:13.56%;">
  <p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;"><br>
  Percentage of Notes Outstanding</font></b></p>
  </td>
  <td width="1%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:1.36%;">
  <p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
  </td>
  <td width="13%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:13.56%;">
  <p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Number of Shares of Common Stock That May&nbsp;Be Sold (1)</font></b></p>
  </td>
  <td width="1%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:1.36%;">
  <p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
  </td>
  <td width="13%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:13.56%;">
  <p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;"><br>
  Percentage of Shares of Common Stock Outstanding</font></b></p>
  </td>
  <td width="1%" valign="bottom" style="padding:0in .7pt 0in .7pt;width:1.36%;">
  <p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
  </td>
 </tr>
 <tr>
  <td width="38%" valign="top" bgcolor="#CCEEFF" style="background:#CCEEFF;border:none;padding:0in .7pt 0in .7pt;width:38.94%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Calyon S/A (2)</font></p>
  </td>
  <td width="1%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;padding:0in .7pt 0in .7pt;width:1.36%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
  </td>
  <td width="1%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;border:none;padding:0in .7pt 0in .7pt;width:1.3%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">$</font></p>
  </td>
  <td width="12%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;border:none;border-top:solid windowtext 1.0pt;padding:0in .7pt 0in .7pt;width:12.28%;">
  <p align="right" style="color:windowtext;margin:0in 0in .0001pt;text-align:right;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">5,000,000</font></p>
  </td>
  <td width="1%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;padding:0in .7pt 0in .7pt;width:1.36%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
  </td>
  <td width="13%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;border:none;padding:0in .7pt 0in .7pt;width:13.56%;">
  <p align="right" style="color:windowtext;margin:0in 0in .0001pt;text-align:right;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">1.74</font></p>
  </td>
  <td width="1%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;padding:0in .7pt 0in .7pt;width:1.36%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">%</font></p>
  </td>
  <td width="13%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;border:none;padding:0in .7pt 0in .7pt;width:13.56%;">
  <p align="right" style="color:windowtext;margin:0in 0in .0001pt;text-align:right;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">91,879</font></p>
  </td>
  <td width="1%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;padding:0in .7pt 0in .7pt;width:1.36%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
  </td>
  <td width="13%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;border:none;padding:0in .7pt 0in .7pt;width:13.56%;">
  <p align="right" style="color:windowtext;margin:0in 0in .0001pt;text-align:right;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">0.15</font></p>
  </td>
  <td width="1%" valign="bottom" bgcolor="#CCEEFF" style="background:#CCEEFF;padding:0in .7pt 0in .7pt;width:1.36%;">
  <p style="color:windowtext;margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">%</font></p>
  </td>
 </tr>
 <tr height="0">
  <td width="291" style="border:none;"></td>
  <td width="10" style="border:none;"></td>
  <td width="9" style="border:none;"></td>
  <td width="91" style="border:none;"></td>
  <td width="10" style="border:none;"></td>
  <td width="101" style="border:none;"></td>
  <td width="13" style="border:none;"></td>
  <td width="101" style="border:none;"></td>
  <td width="10" style="border:none;"></td>
  <td width="101" style="border:none;"></td>
  <td width="13" style="border:none;"></td>
 </tr>
</table>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;font-size:10.0pt;margin:0in 0in .0001pt .75in;text-indent:-.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(1)</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font>Represents
the maximum number of shares of our common stock issuable upon conversion of
all of the holder&#146;s notes, based on the initial conversion rate of 18.3757
shares of our common stock per $1,000 principal amount at maturity of the
notes.&#160; However, this conversion rate
will be subject to adjustment as described under &#147;Description of
Notes&#151;Conversion Rights.&#148;&#160; As a result,
the amount of common stock issuable upon conversion of the notes may increase
or decrease in the future.</p>

<p style="color:windowtext;margin:0in 0in .0001pt .75in;text-indent:-.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;font-size:10.0pt;margin:0in 0in .0001pt .75in;text-indent:-.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(2)</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font>This
selling securityholder is an affiliate of Calyon Securities (USA) Inc., which
is a broker-dealer, and the selling securityholder is a subsidiary of Cr&#233;dit
Agricole S/A, a publicly traded company in France.</p>

<p style="color:windowtext;margin:0in 0in .0001pt .75in;text-indent:-.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Based upon information provided by the selling securityholders, none of
the selling securityholders nor any of their affiliates, officers, directors or
principal equity holders has held any position or office or has had any
material relationship with us within the past three years, except as disclosed
in the Prospectus and this prospectus supplement no. 4.&#160; None of the selling securityholders listed
above will own 1% or more of our outstanding common stock after this offering.</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Selling securityholders who are registered broker-dealers or affiliates
of registered broker-dealers may be deemed to be &#147;underwriters&#148; within the
meaning of the Securities Act.&#160; To our
knowledge, no selling securityholder </font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

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</div>
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<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:0in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">who is a registered broker-dealer or an affiliate of a
registered broker-dealer received any securities as underwriting compensation.</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Information concerning the selling securityholders may change from time
to time and any changed information will be set forth in additional supplements
to the Prospectus if and when necessary.&#160;
In addition, the conversion rate and, therefore, the number of shares of
common stock issuable upon conversion of the notes, is subject to adjustment
under certain circumstances.</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-autospace:none;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Investing in the notes and our
common stock issuable upon conversion of the notes involves risks that are
described in the &#147;Risk Factors&#148; section beginning on page&nbsp;8 of the
Prospectus.</font></b></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-autospace:none;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Neither the Securities and Exchange Commission nor
any state securities commission has approved or disapproved of these securities
or determined if this Prospectus is truthful or complete.&#160; Any representation to the contrary is a
criminal offense.</font></b></p>

<p style="color:windowtext;margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">The date of this
prospectus supplement is December&nbsp;13, 2007.</font></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

<div style="color:windowtext;margin:0in 0in .0001pt;text-autospace:none;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>

<p align="center" style="color:windowtext;margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>

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