-----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,
 A3XV05kLmG99Oishlc6QbCuM2QlyynK9xup4z6Rmik8sUlj4LPbG8Ur200XRZuC8
 w/ZNxe5eM5G65+J44o+tiw==

<SEC-DOCUMENT>0000950134-05-024008.txt : 20051230
<SEC-HEADER>0000950134-05-024008.hdr.sgml : 20051230
<ACCEPTANCE-DATETIME>20051230163042
ACCESSION NUMBER:		0000950134-05-024008
CONFORMED SUBMISSION TYPE:	SC 13D
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20051230
DATE AS OF CHANGE:		20051230
GROUP MEMBERS:		YORKTOWN ENERGY PARTNERS VI LP
GROUP MEMBERS:		YORKTOWN VI COMPANY LP

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HALLADOR PETROLEUM CO
		CENTRAL INDEX KEY:			0000788965
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				841014610
		STATE OF INCORPORATION:			CO
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-37955
		FILM NUMBER:		051294967

	BUSINESS ADDRESS:	
		STREET 1:		1660 LINCOLN ST STE 2700
		CITY:			DENVER
		STATE:			CO
		ZIP:			80264
		BUSINESS PHONE:		3038395505

	MAIL ADDRESS:	
		STREET 1:		1660 LINCOLN STREET
		STREET 2:		SUITE 2700
		CITY:			DENVER
		STATE:			CO
		ZIP:			80264

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KIMBARK OIL & GAS CO /CO/
		DATE OF NAME CHANGE:	19900102

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KIMBARK INC
		DATE OF NAME CHANGE:	19860624

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Yorktown VI Associates LLC
		CENTRAL INDEX KEY:			0001347608
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D

	BUSINESS ADDRESS:	
		STREET 1:		410 PARK AVENUE
		STREET 2:		19TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-515-2100

	MAIL ADDRESS:	
		STREET 1:		410 PARK AVENUE
		STREET 2:		19TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13D
<SEQUENCE>1
<FILENAME>d31684bsc13d.htm
<DESCRIPTION>SCHEDULE 13D
<TEXT>
<HTML>
<HEAD>
<TITLE>sc13d</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="right">
<TABLE style="font-size: 12pt" cellspacing="0" border="0" cellpadding="0"
width="15%">
<!-- Begin Table Head -->
<TR valign="bottom">
<TD width="1%">&nbsp;</TD>
<TD width="98%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
<TD width="1%" style="border-left: 1px solid #000000; border-top: 1px solid
#000000; border-bottom: 1px solid #000000">&nbsp;</TD>
<TD align="center" valign="top" style="border-top: 1px solid #000000;
border-bottom: 1px solid #000000"><DIV style="margin-left:0px;
text-indent:-0px">OMB APPROVAL</DIV></TD>
<TD width="1%" style="border-right: 1px solid #000000; border-top: 1px solid
#000000; border-bottom: 1px solid #000000">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD width="1%" style="border-left: 1px solid #000000">&nbsp;</TD>
<TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">OMB Number:
3235-0145</DIV></TD>
<TD width="1%" style="border-right: 1px solid #000000">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD width="1%" style="border-left: 1px solid #000000">&nbsp;</TD>
<TD valign="top" nowrap><DIV style="margin-left:0px; text-indent:-0px">Expires:
December&nbsp;31, 2005</DIV>
</TD>
<TD width="1%" style="border-right: 1px solid #000000">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD width="1%" style="border-left: 1px solid #000000">&nbsp;</TD>
<TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Estimated
average burden hours per response...15</DIV></TD>
<TD width="1%" style="border-right: 1px solid #000000">&nbsp;</TD>
</TR>
<TR style="font-size: 1px" valign="bottom">
<TD nowrap align="left" colspan="3" style="border-top: 1px solid
#000000">&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>

<DIV style="width: 100%; border-bottom: 2pt solid black; font-size:
1pt">&nbsp;</DIV>
<DIV style="width: 100%; border-bottom: 1pt solid black; font-size:
1pt">&nbsp;</DIV>


<P align="center" style="font-size: 14pt"><B>UNITED STATES<BR>
SECURITIES AND EXCHANGE COMMISSION</B>

<DIV align="center" style="font-size: 12pt"><B>Washington, D.C. 20549</B>
</DIV>

<P align="center" style="font-size: 18pt"><B>SCHEDULE 13D</B>


<P align="center" style="font-size: 12pt"><B>Under the Securities Exchange Act
of 1934<BR>
(Amendment No.&nbsp;&nbsp;)*</B>


<DIV align="center">
<DIV style="font-size: 24pt; margin-top: 16pt; width: 100%; border-bottom: 1px
solid #000000">HALLADOR PETROLEUM COMPANY</DIV>
</DIV>


<DIV align="center" style="font-size: 10pt">(Name of Issuer)
</DIV>


<DIV align="center">
<DIV style="font-size: 10pt; margin-top: 16pt; width: 100%; border-bottom: 1px
solid #000000">Common Stock, par value $.01 per share</DIV>
</DIV>

<DIV align="center" style="font-size: 10pt">(Title of Class of Securities)
</DIV>


<DIV align="center">
<DIV style="font-size: 10pt; margin-top: 16pt; width: 100%; border-bottom: 1px
solid #000000">406092205</DIV>
</DIV>

<DIV align="center" style="font-size: 10pt">(CUSIP Number)
</DIV>


<DIV align="center">
<DIV style="font-size: 10pt; margin-top: 16pt; width: 100%; border-bottom: 1px
solid #000000">Peter A. Leidel<BR>410 Park Avenue, 19th Floor<BR>New York, New
York 10022<BR></DIV>
</DIV>


<DIV align="center" style="font-size: 10pt">(Name, Address and Telephone Number
of Person Authorized to<BR>
Receive Notices and Communications)
</DIV>


<DIV align="center">
<DIV style="font-size: 10pt; margin-top: 16pt; width: 100%; border-bottom: 1px
solid #000000">December 20, 2005</DIV>
</DIV>

<DIV align="center" style="font-size: 10pt">(Date of Event Which Requires Filing
of this Statement)
</DIV>

<P align="left" style="font-size: 10pt">If the filing person has previously
filed a statement on Schedule&nbsp;13G to report the acquisition that is the
subject of this Schedule&nbsp;13D, and is filing this schedule because of
&#167;&#167;240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.
<FONT face="wingdings" size="2">&#111;</FONT>

<P align="left" style="font-size: 10pt"><B>Note: </B>Schedules filed in paper
format shall include a signed original and five copies of the schedule,
including all exhibits. See &#167;240.13d-7 for other parties to whom copies are
to be sent.

<P align="left" style="font-size: 10pt">* The remainder of this cover page shall
be filled out for a reporting person&#146;s initial filing on this form with
respect to the subject class of securities, and for any subsequent amendment
containing information which would alter disclosures provided in a prior cover
page.

<P align="left" style="font-size: 10pt">The information required on the
remainder of this cover page shall not be deemed to be &#147;filed&#148; for the
purpose of Section 18 of the Securities Exchange Act of 1934 (&#147;Act&#148;)
or otherwise subject to the liabilities of that section of the Act but shall be
subject to all other provisions of the Act (however, see the Notes).

<P align="left" style="font-size: 10pt"><B>Persons who respond to the collection
of information contained in this form are not required to respond unless the
form displays a currently valid OMB control number.</B>


<DIV style="width: 100%; border-bottom: 1pt solid black; margin-top: 10pt;
font-size: 1pt">&nbsp;</DIV>
<DIV style="width: 100%; border-bottom: 2pt solid black; font-size:
1pt">&nbsp;</DIV>

<P align="center" style="font-size: 10pt">
</DIV>



<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0"
width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="20%">&nbsp;</TD>
<TD width="55%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="9%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="9%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->


<TR valign="bottom">
<TD valign="top" nowrap><DIV style="margin-left:0px; text-indent:-0px">CUSIP
No.</DIV></TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid #000000">406092205&nbsp;</DIV></TD>
<TD>&nbsp;</TD>
<TD align="left" valign="top">Page</TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid #000000">2&nbsp;</DIV></TD>
<TD>&nbsp;</TD>
<TD align="left" valign="top">of&nbsp;</TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid #000000">8&nbsp;</DIV></TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<P>&nbsp;<DIV style="width: 100%; border: 1px solid black"><DIV align="center">

<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="1"
width="100%">
<!-- Begin Table Head --><TR style="font-size: 1px">
<TD width="5%">&nbsp;</TD>
<TD width="1%" style="border-left: 1px solid #000000">&nbsp;</TD>
<TD width="5%">&nbsp;</TD>
<TD width="5%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="83%">&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>1</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">NAMES OF REPORTING PERSONS:<BR>
<BR>
YORKTOWN ENERGY PARTNERS VI, L.P.</TD>
</TR>
<TR valign="bottom"> <TD style="border-left: 1px solid #000000">&nbsp;</TD> <TD
colspan="4" align="left">&nbsp;</TD> </TR> <TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
(ENTITIES ONLY):<BR>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"></TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>2</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
(SEE INSTRUCTIONS):<BR><BR></TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">(a)&nbsp;&nbsp;&nbsp;<FONT face="wingdings" size="2">&#111;</FONT>&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">(b)&nbsp;&nbsp;&nbsp;<FONT face="wingdings" size="2">&#111;</FONT>&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>3</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">SEC USE ONLY:</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>4</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">SOURCE OF FUNDS (SEE INSTRUCTIONS):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="11" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="11" align="left">WC</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>5</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"><FONT face="wingdings" size="2">&#111;</FONT></TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>6</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CITIZENSHIP OR PLACE OF ORGANIZATION:</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">Delaware
</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>7</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SOLE VOTING POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">NUMBER OF</TD>
<TD>&nbsp;</TD>
<TD align="left">0</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">SHARES</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>8</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SHARED VOTING POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">BENEFICIALLY</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">OWNED BY</TD>
<TD>&nbsp;</TD>
<TD>3,829,894</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>


<TR valign="bottom">
<TD align="center" colspan="3">EACH</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>9</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SOLE DISPOSITIVE POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">REPORTING</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">PERSON</TD>
<TD>&nbsp;</TD>
<TD align="left">0</TD>
</TR>
<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">WITH</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>10</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SHARED DISPOSITIVE POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD align="left">3,829,894</TD>
</TR>
<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>11</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH
REPORTING PERSON:</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">3,829,894(1)</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>12</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK IF THE AGGREGATE AMOUNT IN ROW
(11)&nbsp;EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"><FONT face="wingdings" size="2">&#111;</FONT>
</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>13</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW
(11):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">42.6&#37;(2)</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>14</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">PN</TD>
</TR>
<!-- End Table Body --></TABLE>
</DIV>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(1)&nbsp;Yorktown VI Company LP is the sole general partner of Yorktown Energy Partners VI,
L.P. Yorktown VI Associates LLC is the sole general partner of Yorktown VI Company LP. As a
result, Yorktown VI Associates LLC may be deemed to share the power to vote or direct the vote or
to dispose or direct the disposition of the shares owned by Yorktown Energy Partners VI, L.P.
Yorktown VI Company LP and Yorktown VI Associates LLC disclaim beneficial ownership of the
securities owned by Yorktown Energy Partners VI, L.P. in excess of their pecuniary interests
therein.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(2)&nbsp;Based on 7,093,150 shares of common stock issued and outstanding as of November&nbsp;14, 2005 as
disclosed by Hallador Petroleum Company in its Form 10-QSB filed with the Securities and Exchange
Commission on November&nbsp;14, 2005 and 1,893,169 shares of common stock issued to Yorktown on December
20, 2005.
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0"
width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="20%">&nbsp;</TD>
<TD width="55%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="9%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="9%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->


<TR valign="bottom">
<TD valign="top" nowrap><DIV style="margin-left:0px; text-indent:-0px">CUSIP
No.</DIV></TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid #000000">406092205&nbsp;</DIV></TD>
<TD>&nbsp;</TD>
<TD align="left" valign="top">Page</TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid
#000000">3&nbsp;</DIV></TD>
<TD>&nbsp;</TD>
<TD align="left" valign="top">of&nbsp;</TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid
#000000">8&nbsp;</DIV></TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<P>&nbsp;<DIV style="width: 100%; border: 1px solid black"><DIV align="center">

<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="1"
width="100%">
<!-- Begin Table Head --><TR style="font-size: 1px">
<TD width="5%">&nbsp;</TD>
<TD width="1%" style="border-left: 1px solid #000000">&nbsp;</TD>
<TD width="5%">&nbsp;</TD>
<TD width="5%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="83%">&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>1</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">NAMES OF REPORTING PERSONS:<BR>
<BR>
YORKTOWN VI COMPANY LP</TD>
</TR>
<TR valign="bottom"> <TD style="border-left: 1px solid #000000">&nbsp;</TD> <TD
colspan="4" align="left">&nbsp;</TD> </TR> <TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
(ENTITIES ONLY):<BR>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"></TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>2</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
(SEE INSTRUCTIONS):<BR><BR></TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">(a)&nbsp;&nbsp;&nbsp;<FONT face="wingdings"
size="2">&#111;</FONT>&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">(b)&nbsp;&nbsp;&nbsp;<FONT face="wingdings"
size="2">&#111;</FONT>&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>3</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">SEC USE ONLY:</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>4</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">SOURCE OF FUNDS (SEE INSTRUCTIONS):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="11" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="11" align="left">N/A</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>5</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"><FONT face="wingdings" size="2">&#111;</FONT></TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>6</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CITIZENSHIP OR PLACE OF ORGANIZATION:</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">Delaware
</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>7</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SOLE VOTING POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">NUMBER OF</TD>
<TD>&nbsp;</TD>
<TD align="left">0</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">SHARES</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>8</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SHARED VOTING POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">BENEFICIALLY</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">OWNED BY</TD>
<TD>&nbsp;</TD>
<TD>3,829,894</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>


<TR valign="bottom">
<TD align="center" colspan="3">EACH</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>9</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SOLE DISPOSITIVE POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">REPORTING</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">PERSON</TD>
<TD>&nbsp;</TD>
<TD align="left">0</TD>
</TR>
<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">WITH</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>10</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SHARED DISPOSITIVE POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD align="left">3,829,894</TD>
</TR>
<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>11</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH
REPORTING PERSON:</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">3,829,894(1)</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>12</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK IF THE AGGREGATE AMOUNT IN ROW
(11)&nbsp;EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"><FONT face="wingdings" size="2">&#111;</FONT>
</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>13</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW
(11):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">42.6&#37;(2)</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>14</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">PN</TD>
</TR>
<!-- End Table Body --></TABLE>
</DIV>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(1)&nbsp;Yorktown VI Company LP is the sole general partner of Yorktown Energy Partners VI,
L.P. Yorktown VI Associates LLC is the sole general partner of Yorktown VI Company LP. As a
result, Yorktown VI Associates LLC may be deemed to share the power to vote or direct the vote or
to dispose or direct the disposition of the shares owned by Yorktown Energy Partners VI, L.P.
Yorktown VI Company LP and Yorktown VI Associates LLC disclaim beneficial ownership of the
securities owned by Yorktown Energy Partners VI, L.P. in excess of their pecuniary interests
therein.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(2)&nbsp;Based on 7,093,150 shares of common stock issued and outstanding as of November&nbsp;14, 2005 as
disclosed by Hallador Petroleum Company in its Form 10-QSB filed with the Securities and Exchange
Commission on November&nbsp;14, 2005 and 1,893,169 shares of common stock issued to Yorktown on December
20, 2005.
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0"
width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="20%">&nbsp;</TD>
<TD width="55%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="9%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="9%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->


<TR valign="bottom">
<TD valign="top" nowrap><DIV style="margin-left:0px; text-indent:-0px">CUSIP
No.</DIV></TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid
#000000">406092205&nbsp;</DIV></TD>
<TD>&nbsp;</TD>
<TD align="left" valign="top">Page</TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid
#000000">4&nbsp;</DIV></TD>
<TD>&nbsp;</TD>
<TD align="left" valign="top">of&nbsp;</TD>
<TD>&nbsp;</TD>
<TD align="center" valign="top"><DIV style="border: 1px solid
#000000">8&nbsp;</DIV></TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<P>&nbsp;<DIV style="width: 100%; border: 1px solid black"><DIV align="center">

<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="1"
width="100%">
<!-- Begin Table Head --><TR style="font-size: 1px">
<TD width="5%">&nbsp;</TD>
<TD width="1%" style="border-left: 1px solid #000000">&nbsp;</TD>
<TD width="5%">&nbsp;</TD>
<TD width="5%">&nbsp;</TD>
<TD width="1%">&nbsp;</TD>
<TD width="83%">&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>1</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">NAMES OF REPORTING PERSONS:<BR>
<BR>
YORKTOWN VI ASSOCIATES LLC</TD>
</TR>
<TR valign="bottom"> <TD style="border-left: 1px solid #000000">&nbsp;</TD> <TD
colspan="4" align="left">&nbsp;</TD> </TR> <TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
(ENTITIES ONLY):<BR>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"></TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>2</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
(SEE INSTRUCTIONS):<BR><BR></TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">(a)&nbsp;&nbsp;&nbsp;<FONT face="wingdings"
size="2">&#111;</FONT>&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">(b)&nbsp;&nbsp;&nbsp;<FONT face="wingdings"
size="2">&#111;</FONT>&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>3</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">SEC USE ONLY:</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>4</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">SOURCE OF FUNDS (SEE INSTRUCTIONS):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="11" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="11" align="left">WC</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>5</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS
REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"><FONT face="wingdings" size="2">&#111;</FONT></TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>6</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CITIZENSHIP OR PLACE OF ORGANIZATION:</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">Delaware
</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>7</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SOLE VOTING POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">NUMBER OF</TD>
<TD>&nbsp;</TD>
<TD align="left">0</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">SHARES</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>8</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SHARED VOTING POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">BENEFICIALLY</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">OWNED BY</TD>
<TD>&nbsp;</TD>
<TD>3,829,894</TD>
</TR>

<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>


<TR valign="bottom">
<TD align="center" colspan="3">EACH</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>9</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SOLE DISPOSITIVE POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">REPORTING</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">PERSON</TD>
<TD>&nbsp;</TD>
<TD align="left">0</TD>
</TR>
<TR style="font-size: 1px">
<TD colspan="3">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000; border-left: 1px solid
#000000; border-right: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
<TD align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD align="center" colspan="3">WITH</TD>
<TD valign="middle" align="center" rowspan="3" style="border-left: 1px solid
#000000; border-right: 1px solid #000000"><FONT style="font-size:
18pt"><B>10</B></FONT></TD>
<TD>&nbsp;</TD>
<TD align="left">SHARED DISPOSITIVE POWER:</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD>&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD align="center" colspan="3">&nbsp;</TD>
<TD>&nbsp;</TD>
<TD align="left">3,829,894</TD>
</TR>
<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>11</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH
REPORTING PERSON:</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">3,829,894(1)</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>12</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">CHECK IF THE AGGREGATE AMOUNT IN ROW
(11)&nbsp;EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left"><FONT face="wingdings" size="2">&#111;</FONT>
</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid
#000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size: 18pt"><B>13</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW
(11):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">42.6&#37;(2)</TD>
</TR>

<TR style="font-size: 1px">
<TD style="border-top: 1px solid #000000">&nbsp;</TD>
<TD style="border-left: 1px solid #000000; border-top: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>

<TR valign="bottom">
<TD valign="middle" align="center" rowspan="3"><FONT style="font-size:
18pt"><B>14</B></FONT></TD>
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">&nbsp;</TD>
</TR>
<TR valign="bottom">
<TD style="border-left: 1px solid #000000">&nbsp;</TD>
<TD colspan="4" align="left">PN</TD>
</TR>
<!-- End Table Body --></TABLE>
</DIV>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(1)&nbsp;Yorktown VI Company LP is the sole general partner of Yorktown Energy Partners VI,
L.P. Yorktown VI Associates LLC is the sole general partner of Yorktown VI Company LP. As a
result, Yorktown VI Associates LLC may be deemed to share the power to vote or direct the vote or
to dispose or direct the disposition of the shares owned by Yorktown Energy Partners VI, L.P.
Yorktown VI Company LP and Yorktown VI Associates LLC disclaim beneficial ownership of the
securities owned by Yorktown Energy Partners VI, L.P. in excess of their pecuniary interests
therein.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(2)&nbsp;Based on 7,093,150 shares of common stock issued and outstanding as of November&nbsp;14, 2005 as
disclosed by Hallador Petroleum Company in its Form 10-QSB filed with the Securities and Exchange
Commission on November&nbsp;14, 2005 and 1,893,169 shares of common stock issued to Yorktown on December
20, 2005.
</DIV>

<P align="center" style="font-size: 10pt">&nbsp;
</DIV>
<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">



<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;1. SECURITY AND ISSUER.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This Schedule&nbsp;13D relates to the common stock (the &#147;Common Stock&#148;) of Hallador Petroleum
Company (the &#147;Company&#148;) whose principal executive offices are located at 1660 Lincoln Street,
Suite&nbsp;2700, Denver, CO 80264.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;2. IDENTITY AND BACKGROUND.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This statement is filed by Yorktown Energy Partners VI, L.P., a Delaware limited partnership
(&#147;Yorktown&#148;), Yorktown VI Company LP, a Delaware limited partnership (the &#147;General Partner&#148;) and
Yorktown VI Associates LLC, a Delaware limited liability company (the &#147;LLC&#148;). The principal office
and business address of Yorktown, the General Partner and the LLC is 410 Park Avenue,
19<SUP style="font-size: 85%; vertical-align: text-top">th</SUP> Floor, New York, New York, 10022. The principal business of Yorktown is investing
in equity securities of energy investments. The principal business of the general partner is
managing Yorktown. The principal business of the LLC is managing the General Partner.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Yorktown, the General Partner and the LLC have not, during the last five years, been convicted
in a criminal proceeding (excluding traffic violations or similar misdemeanors).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Yorktown, the General Partner and the LLC have not, during the last five years, been a party
to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a
result of such proceeding was or is subject to a judgment, decree or final order enjoining future
violations of, or prohibiting or mandating activities subject to, federal or state securities laws
or finding any violation with respect to such laws.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;3. SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Yorktown used $8,425,766.80 of its working capital to purchase the 3,829,894 shares.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;4. PURPOSE OF TRANSACTION.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Yorktown acquired the 3,829,894 shares of common stock for investment purposes. As of the
date hereof, Yorktown, the General Partner and the LLC have not formulated any specific plans or
proposals which relate to or would result in: (a)&nbsp;the acquisition by any person of additional
securities of the Company or the disposition of securities of the Company; (b)&nbsp;an extraordinary
corporate transaction, such as a merger, reorganization or liquidation involving the Company; (c)&nbsp;a
sale or transfer of a material amount of assets of the Company; (d)&nbsp;any change in the present board
of directors or management of the Company, including any plans or proposals to change the number or
term of directors or to fill any existing vacancies on the board; (e)&nbsp;any material change in the
present capitalization or dividend policy of the Company; (f)&nbsp;any other material change in the
Company&#146;s business or corporate structure; (g)&nbsp;changes in the Company&#146;s charter or bylaws or other
actions which may impede the acquisition of control of the Company by any person; (h)&nbsp;causing a
class of securities of the Company to be delisted from a national securities exchange or to cease
to be authorized to be quoted in an inter-dealer quotation (i)&nbsp;causing a class of equity securities
of the Company to become eligible for termination of registration pursuant to Section&nbsp;12(g)(4) of
the Securities Exchange Act of 1934, as amended (the &#147;Act&#148;); or (j)&nbsp;any action similar to any of
those enumerated above.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;5. INTEREST IN SECURITIES OF THE ISSUER.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;As of December&nbsp;20, 2005, Yorktown owned 3,829,894 shares of common stock, representing
42.6% of the Company&#146;s outstanding shares of common stock (based on 7,093,150 shares of common
stock issued and outstanding as of November&nbsp;14, 2005 as disclosed by Hallador Petroleum Company in
its Form 10-QSB filed with the Securities and Exchange Commission on November&nbsp;14, 2005 and
1,893,169 shares of common stock issued to Yorktown on December&nbsp;20, 2005).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;Yorktown&#146;s general partner, Yorktown VI Company LLC, has the sole voting power and sole
disposition power with respect to the shares of common stock owned by Yorktown.
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt">Page 5 of 8
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">




<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;None.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d)&nbsp;No person other than Yorktown has the right to receive or the power to direct the receipt
of dividends from, or the proceeds from the sale of, the shares of common stock reported on this
Schedule&nbsp;13D.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e)&nbsp;N/A.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO SECURITIES OF THE
ISSUER.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;None.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;7. MATERIAL TO BE FILED AS EXHIBITS</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Joint Filing Agreement dated December&nbsp;30, 2005.
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt">Page 6 of 8
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">




<DIV align="center" style="font-size: 10pt; margin-top: 18pt">SIGNATURES
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">After reasonable inquiry and to the best of my knowledge and belief, I certify that the information
set forth in this statement is true, complete and correct.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt">Date: December&nbsp;30, 2005
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="43%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="51%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD colspan="3" valign="top" align="left">YORKTOWN ENERGY PARTNERS VI, LP</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Yorktown VI Company LP,<br>
its general partner</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Yorktown VI Associates LLC,<br>
its general partner</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/&nbsp;&nbsp;W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Name:&nbsp;&nbsp;W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Title:&nbsp;&nbsp;Member</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD colspan="3" valign="top" align="left">YORKTOWN VI COMPANY LP</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Yorktown VI Associates LLC,<br>
its general partner</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/&nbsp;&nbsp;W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Name:&nbsp;&nbsp;W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Title:&nbsp;&nbsp;Member</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD colspan="3" valign="top" align="left">YORKTOWN VI ASSOCIATES LLC</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/&nbsp;&nbsp;W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Name:&nbsp;&nbsp;W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Title:&nbsp;&nbsp;Member</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<P align="center" style="font-size: 10pt">Page 7 of 8
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><U>JOINT FILING AGREEMENT</U>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In accordance with Rule&nbsp;13d-1(k) under the Securities Exchange Act of 1934, the persons named
below agree to the joint filing on behalf of each of them of a Statement on Schedule&nbsp;13D (including
amendments thereto) with respect to the common stock of HALLADOR PETROLEUM COMPANY and further
agree that this Joint Filing Agreement be included as an Exhibit to such joint filings. In
evidence thereof each of the undersigned, being duly authorized, hereby execute this Agreement on
the date set forth opposite its name.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt">Date: December&nbsp;30, 2005
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="2%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="43%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="51%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD colspan="3" valign="top" align="left">YORKTOWN ENERGY PARTNERS VI, LP</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Yorktown VI Company LP,<br>
its general partner</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Yorktown VI Associates LLC,<br>
its general partner</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Name:  W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Title:  Member</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD colspan="3" valign="top" align="left">YORKTOWN VI COMPANY LP</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Yorktown VI Associates LLC,<br>
its general partner</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/  W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Name:  W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Title:  Member</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD colspan="3" valign="top" align="left">YORKTOWN VI ASSOCIATES LLC</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/  W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Name:  W. Howard Keenan</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Title:  Member</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt">Page 8 of 8
</DIV>



<P align="center" style="font-size: 10pt">&nbsp;
</DIV>


</BODY>
</HTML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
