----

----

|   | PETROLEUM      DEVELOPMENT CORPORATION |
|--------|----------------------------------------|
|   | A      Nevada Corporation              |
|   |                                   |
|   | BY:                                    | /s/      James P. Wason |
|   | James      P. Wason                    |
|   | Director      of Land                  |

| STATE      OF WELD      | ) |    |
|-------------------------|---|---------|
|                    | ) | TO-WIT: |
| COUNTY      OF COLORADO | ) |    |

|   |   | /s/      Carrie Eggleston                                                                                                                           |
|--------|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------|
|        |   | Carrie      EgglestonNotary      Public-      ColoradoCounty      of WeldMy      Commission expires: November 12,2006 |

----

|   | Exhibit      "A"                                                                                                                                                                                   |   | Weld      County, Colorado |
|--------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|----------------------------|
|   | Attached      to and made part of that Assignment of Working Interest dated July 14,2006      by and between Petroleum Development Corporation and Rockies Region      Private Limited Partnership |   |                       |

| AFE      # |   | WELL      NAME    |   | WORKING      INT.  |   | TWP  |   | RNG    |   |        SEC |   | Q/Q    |   | SPUD      DATE  |   |        LEASE# |   | LESSOR                                                                           |   | LESSEE                                 |   | LEASE      DATE               |   | BOOK  |   | PAGE     |   | RECEPTION |
|------------|--------|------------------------|--------|-------------------------|--------|-----------|--------|--------|--------|-----------------|--------|--------|--------|----------------------|--------|--------------------|--------|----------------------------------------------------------------------------------|--------|----------------------------------------|--------|-------------------------------|--------|------------|--------|---------------|--------|-----------|
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   |               |   |                                                                             |   |                                   |   |                          |   |       |   |          |   |      |
| 6024       |   | Wells      Ranch 24-2  |   | 0.9985                  |   | 5N        |   | 63W    |   | 2               |   | SESW   |   | 01/16/06             |   | 687600             |   | Wells      Ranch, a Colorado general partnership, and Katherine Wells      Calve |   | Petroleum      Development Corporation |   | August 20,      2002     |   | -          |   |        - |   | 2996355   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   |               |   |                                                                             |   |                                   |   |                          |   |       |   |          |   |      |
| 6026       |   | Wells      Ranch 33-2  |   | 0.9985                  |   | 5N        |   | 63W    |   | 2               |   | NWSE   |   | 01/22/06             |   | 687600             |   | Wells      Ranch, a Colorado general partnership, and Katherine Wells      Calve |   | Petroleum      Development Corporation |   | August 20,      2002     |   | -          |   |        - |   | 2996355   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   |               |   |                                                                             |   |                                   |   |                          |   |       |   |          |   |      |
| 6027       |   | Wells      Ranch 34-2  |   | 0.9985                  |   | 5N        |   | 53W    |   | 2               |   | SWSE   |   | 01/26/06             |   | 687600             |   | Wells      Ranch, a Colorado general partnership, and Katherine Wells      Calve |   | Petroleum      Development Corporation |   | August 20,      2002     |   | -          |   |        - |   | 2996355   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   |               |   |                                                                             |   |                                   |   |                          |   |       |   |          |   |      |
| 6030       |   | Wells      Ranch 43-2  |   | 0.9985                  |   | 5N        |   | 63W    |   | 2               |   | NE5E   |   | 01/30/06             |   | 687600             |   | Wells      Ranch, a Colorado general partnership, and Katherine Wells      Calve |   | Petroleum      Development Corporation |   | August 20,      2002     |   | -          |   |        - |   | 2996355   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   |               |   |                                                                             |   |                                   |   |                          |   |       |   |          |   |      |
| 6022       |   | State      31-4        |   | 0.9985                  |   | 5N        |   | 63W    |   | 4               |   | NWNE   |   | 01/04/06             |   | 679000             |   | State      of Colorado 81/6521-S                                                 |   | Rocfc      Oil Corporation             |   | June 1,      1981        |   | 1207       |   |        - |   | 2153523   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   |               |   |                                                                             |   |                                   |   |                          |   |       |   |          |   |      |
| 6023       |   | State      41-4        |   | 0.9985                  |   | 5N        |   | 63W    |   | 4               |   | NENE   |   | 01/11/06             |   | 679000             |   | State      of Colorado 81/6521-S                                                 |   | Rock      Oil Corporation              |   | June 1,      1981        |   | 1207       |   |        - |   | 2153523   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   |               |   |                                                                             |   |                                   |   |                          |   |       |   |          |   |      |
| 5373       |   | Wells      Ranch 44-14 |   | 0.9985                  |   | 5N        |   | 63W    |   | 14              |   | SESE   |   | 12/31/05             |   | 687700             |   | Wells      Ranch, a Colorado general partnership, and Katherine Weils      Calve |   | Petroleum      Development Corporation |   | November 14,      2003   |   | -          |   | -             |   | 3130700   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   |               |   |                                                                             |   |                                   |   |                          |   |       |   |          |   |      |
| 5130       |   | Pettinger      44-2    |   | 0.9985                  |   | 6N        |   | 64W    |   | 2               |   | SESE   |   | 12/28/05             |   | 746100             |   | Allen J. Heckman      and Barbie E. Heckman                  |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173747   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 746200             |   | Dean Jake Kerbs                                                        |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173748   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 759100             |   | Thomas James      Kerbs, Jr. and Deborah Ann Kerbs                     |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3192849   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 745300             |   | Patricia Lee McDonough                                                 |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3171841   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 764400             |   | Darin      L. Naibauer                                                      |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173743   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 746500             |   | Duane R. Naibauer                                                      |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173744   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 746300             |   | Dennis S. Naibauer                                                     |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173749   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 751700             |   | Diane K. Carlson                                                       |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3178350   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 751800             |   | Darla R. Stout                                                         |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3178352   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 799100             |   | The      Travelers Insurance Company                                             |   | Petroleum      Development Corporation |   | April 1,       2005 |   | -          |   | -             |   | 3315666   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   |               |   |                                                                             |   |                                   |   |                          |   |       |   |          |   |      |
| 6004       |   | Pettinger      33-2    |   | 0.9985                  |   | 6N        |   | 64W    |   | 2               |   | NWSE   |   | 01/05/06             |   | 746100             |   | Allen J. Heckman      and Barbie E. Heckman                  |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173747   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 746200             |   | Dean Jake Kerbs                                                        |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173748   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 759100             |   | Thomas James      Kerbs, Jr. and Deborah Ann Kerbs                     |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3192849   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 745300             |   | Patricia Lee McDonough                                                 |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3171841   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 764400             |   | Darin      L. Naibauer                                                      |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173743   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 746500             |   | Duane R. Naibauer                                                      |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173744   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 746300             |   | Dennis S. Naibauer                                                     |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3173749   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 751700             |   | Diane K. Carlson                                                       |   | Petroleum      Development Corporation |   | February 24.      2004   |   | -          |   | -             |   | 3178350   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 751800             |   | Darla R.      Stout                                                         |   | Petroleum      Development Corporation |   | February 24,      2004   |   | -          |   | -             |   | 3178352   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 853700             |   | The      Noah Family Living Trust                                           |   | Petroleum      Development Corporation |   | January 17,      2006    |   | -          |   | -             |   | 3364133   |
|       |   |                   |   |                    |   |      |   |   |   |            |   |   |   |                 |   | 799100             |   | The      Travelers Insurance Company                                             |   | Petroleum      Development Corporation |   | April 1,      2005       |   | -          |   | -             |   | 3315666   |

----

|   | Exhibit      "A"                                                                                                                                                                                    |   | Weld      County, Colorado |
|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|----------------------------|
|   | Attached      to and made part of that Assignment of Working Interest dated July 14,      2006 by and between Petroleum Development Corporation and Rockies Region      Private Limited Partnership |   |                       |

| AFE#   |   | WELL      NAME        |   | WORKING      INT. |   | TWP    |   | RNG    |   | SEC    |   | Q/Q    |   | SPUD      DATE |   | LEASE*       |   | LESSOR                                                                                                                                                                                                        |   | LESSEE                                 |   | LEASE      DATE           |   | BOOK   |   | PAGE  |   | RECEPTION  |
|--------|--------|-----------------------|--------|-------------------|--------|--------|--------|--------|--------|--------|--------|--------|--------|----------------|--------|--------------|--------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|----------------------------------------|--------|---------------------------|--------|--------|--------|------------|--------|-----------------|
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6096   |   | Phinney      43-10    |   | 0.9985            |   | 6N     |   | 64W    |   | 10     |   | NESE   |   | 02/05/06       |   | 758700       |   | Myron A,      Phinney and Elizabeth M Phinney                                                                                                                                             |   | Petroleum      Development Corporation |   | May 17,      2004    |   | -      |   | -          |   | 3189023         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6096   |   | Phinney      43-10    |   | 0.9985            |   | 6N     |   | 64W    |   | 10     |   | NESE   |   | 02/05/06       |   | 761100       |   | Walter James Henderson.      III. Randy Lee Henderson and Rick Mark Henderson.      Successor Co-Trustees of the Walter J. and Isabelle      I.Henderson      Trust   |   | Petroleum      Development Corporation |   | May 14,      2004    |   | -      |   | -          |   | 3201750         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 763400       |   | David Neil Blomquist      and Susan J. Blomquist                                                                                                                                          |   | Petroleum      Development Corporation |   | July 22,2004         |   | -      |   | -          |   | 320B262         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6095   |   | Phinney      34-10    |   | 0.9985            |   | 6N     |   | 64W    |   | 10     |   | SWSE   |   | 02/09/06       |   | 761200       |   | Walter James Henderson,      III, Randy Lee Henderson and Rick Mark Henderson,      Successor Co-Trustees of the Walter J. and Isabelle.      I. Henderson      Trust |   | Petroleum      Development Corporation |   | May 14.2004          |   | -      |   | :          |   | 3201751         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 760800  |   | Francine H. Nealy                                                                                                                                                                                   |   | Petroleum      Development Corporation |   | May 18,2004          |   | -      |   | -          |   | 3201745         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6097   |   | Adams      41-10      |   | 0.9985            |   | 6N     |   | 64W    |   | 10     |   | NENE   |   | 02/13/06       |   | 758500       |   | June A. Adams                                                                                                                                                                                       |   | Petroleum      Development Corporation |   | April 22,      2004  |   | -      |   | -          |   | 3189021         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 75B100       |   | Alice Lucille Heidenreich,      Jack O. Heidenreich and      Pamela J. Heidenreich                                                                                              |   | Petroleum      Development Corporation |   | April 22,      2004  |   | -      |   | -          |   | 3184274         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 755100       |   | Arnold      C. Hoffman and Donna J. Hoffman                                                                                                                                                         |   | Petroleum      Development Corporation |   | April 22,      2004  |   | -      |   | -          |   | 3179778         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6098   |   | Wolfrum      32-10    |   | 0.9985            |   | 6N     |   | 64W    |   | 10     |   | SWNE   |   | 02/18/06       |   | 759300       |   | Jimmie L. Wolfrum      and Sharon M. Wolfrum                                                                                                                                              |   | Petroleum      Development Corporation |   | May 12.      2004    |   | -      |   | -          |   | 3192851         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 754900       |   | Arnold      C. Hoffman and Donna J. Hoffman                                                                                                                                                         |   | Petroleum      Development Corporation |   | April 22,      2004  |   | -      |   | -          |   | 3179779         |
| 6034   |   | Hungenberg      21-16 |   | 0.9985            |   | 6N     |   | 65W    |   | 16     |   | NENW   |   | 03/05/06       |   | 803100       |   | Hungenberg      Produce, Inc.                                                                                                                                                                                 |   | Petroleum      Development Corporation |   | August 18,      2005 |   | -      |   | -          |   | 3333948         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6035   |   | Hungenberg      22-16 |   | 0.9985            |   | 6N     |   | 65W    |   | 16     |   | SENW   |   | 03/10/06       |   | 8C3100       |   | Hungenberg      Produce, Inc.                                                                                                                                                                                 |   | Petroleum      Development Corporation |   | August 18,      2005 |   | -      |   | -          |   | 3333948         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6032   |   | Hungenberg      21-17 |   | 0.9985            |   | 6N     |   | 65W    |   | 17     |   | NENW   |   | 02/23/06       |   | 802900       |   | Michael B. Hungenberg and Paul D. Hungenberg                                                                                                                                    |   | Petroleum      Development Corporation |   | August 18,      2005 |   | -      |   | -          |   | 3333946         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6033   |   | Hungenberg      22-17 |   | 0.9985            |   | 6N     |   | 65W    |   | 17     |   | SENW   |   | 02/28/06       |   | 802900       |   | Michael B. Hungenberg      and Paul D. Hungenberg                                                                                                                                         |   | Petroleum      Development Corporation |   | August 18,      2005 |   | -      |   | -          |   | 3333946         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6037   |   | Hungenberg      14-33 |   | 0.9985            |   | 6N     |   | 65W    |   | 33     |   | SWSW   |   | 03/05/06       |   | 803000       |   | Michael B. Hungenberg      and Paul D. Hungenberg                                                                                                                                                   |   | Petroleum      Development Corporation |   | August 18,      2005 |   | -      |   | -          |   | 3333947         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6036   |   | Hungenberg      13-33 |   | 0.9985            |   | 6N     |   | 65W    |   | 33     |   | NWSW   |   | 03/10/06       |   | 803000       |   | Michael B. Hungenberg      and Paul D. Hungenberg                                                                                                                                         |   | Petroleum      Development Corporation |   | August 18,      2005 |   | -      |   | -          |   | 3333947         |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                                                                                                                                                                                          |   |                                   |   |                      |   |   |   |       |   |            |
| 6133   |   | Anderson      32-10   |   | 0.9985            |   | 6N     |   | 66W    |   | 10     |   | SWNE   |   | 03/21/06       |   | 780300       |   | Don      Anderson, Inc., a Colorado Corporation                                                                                                                                                               |   | Petroleum      Development Corporation |   | March 2,      2006   |   | .      |   | .          |   | 3389467         |

----

|   | Exhibit      "A"                                                                                                                                                                                         |   | Weld      County, Colorado |
|--------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|----------------------------|
|   | Attached      to and made part of that Assignment of Working Interest dated July 14,      2006 by and between Petroleum      Development Corporation and Rockies Region Private Limited      Partnership |   |                       |

| AFE#   |   | WELL      NAME        |   | WORKING      INT. |   | TWP    |   | RNG    |   | SEC    |   | Q/Q    |   | SPUD      DATE |   | LEASE# |   | LESSOR                                                                     |   | LESSEE                                           |   | LEASE      DATE              |   | BOOK   |   |  PAGE |   | RECEPTION |
|--------|--------|-----------------------|--------|-------------------|--------|--------|--------|--------|--------|--------|--------|--------|--------|----------------|--------|--------|--------|----------------------------------------------------------------------------|--------|--------------------------------------------------|--------|------------------------------|--------|--------|--------|------------|--------|-----------|
| 6012   |   | Dillard      33-20    |   | 0.9985            |   | 7N     |   | 64W    |   | 20     |   | NWSE   |   | 02/13/06       |   | 772900 |   | Dillard      Family LLC, a Colorado Limiled Liability Company              |   | Petroleum      Development Corporation Petroleum |   | September 13,      2004 |   | -      |   | -          |   | 3228247   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 777000 |   | Mary Beth Elizabeth Rivera                                  |   | Development      Corporation                     |   | September 13,      2004 |   | -      |   | -          |   | 3235727   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778900 |   | Gretchen Lynne Groves Webb                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3247199   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778100 |   | Jane      Gwynne Groves                                                    |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3242744   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 776400 |   | Julianne      Groves                                                       |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3233836   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                       |   |                                             |   |                         |   |   |   |       |   |      |
| 6010   |   | Dillard      43-20    |   | 0.99B5            |   | 7N     |   | 64W    |   | 20     |   | NESE   |   | 01/10/06       |   | 772900 |   | Dillard      Family LLC, a Colorado Limited Liability Company              |   | Petroleum      Development Corporation           |   | September 13.      2004 |   | -      |   | -          |   | 3228247   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 777000 |   | Mary Beth Elizabeth Rivera                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3235727   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778900 |   | Gretchen Lynne Groves Webb                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3247199   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778100 |   | Jane      Gwynne Groves                                                    |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3242744   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 776400 |   | Julianne      Groves                                                       |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3233836   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                       |   |                                             |   |                         |   |   |   |       |   |      |
| 6015   |   | Dillard      32-20    |   | 0.9985            |   | 7N     |   | 64W    |   | 20     |   | SWNE   |   | 02/28/06       |   | 772900 |   | Dillard      Family LLC, a Colorado Limited Liability Company              |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3228247   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 777000 |   | Mary Beth Elizabeth Rivera                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3235727   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778900 |   | Gretchen Lynne Groves Webb                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3247199   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778100 |   | Jane      Gwynne Groves                                                    |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3242744   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 776400 |   | Julianne      Groves                                                       |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3233836   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                       |   |                                             |   |                         |   |   |   |       |   |      |
| 6014   |   | Dillard      42-20    |   | 0.9985            |   | 7N     |   | 64W    |   | 20     |   | SENE   |   | 02/24/06       |   | 772900 |   | Dillard Famlfy      LLC, a Colorado Limited Liability Company         |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3228247   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 777000 |   | Mary Beth Elizabeth Rivera                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3235727   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778900 |   | Gretchen Lynne Groves Webb                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3247199   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778100 |   | Jane      Gwynne Groves                                                    |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3242744   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 776400 |   | Julianne      Groves                                                       |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3233836   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                       |   |                                             |   |                         |   |   |   |       |   |      |
| 6013   |   | Dillard      34-20    |   | 0.9985            |   | 7N     |   | 64W    |   | 20     |   | SWSE   |   | 02/18/06       |   | 772900 |   | Dillard      Family LLC, 3      Colorado Limited Liability Company         |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3228247   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 777000 |   | Mary Beth Elizabeth Rivera                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3235727   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778900 |   | Gretchen Lynne Groves Webb                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3247199   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778100 |   | Jane      Gwynne Groves                                                    |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3242744   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 776400 |   | Julianne      Groves                                                       |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3233336   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                       |   |                                             |   |                         |   |   |   |       |   |      |
| 6011   |   | Dillard      44-20    |   | 0.9935            |   | 7N     |   | 64W    |   | 20     |   | SESE   |   | 01/15/06       |   | 772900 |   | Dillard      Family LLC, a Colorado Limited Liability Company              |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3228247   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 777000 |   | Mary Beth Elizabeth Rivera                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3235727   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778900 |   | Gretchen Lynne Groves Webb                                  |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3247199   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 778100 |   | Jane      Gwynne Groves                                                    |   | Petroleum      Development Corporation           |   | September 13,      2004 |   | -      |   | -          |   | 3242744   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 776400 |   | Julianne      Groves                                                       |   | Petroleum      Development Corporation           |   | September 13.      2004 |   | -      |   | -          |   | 3233836   |
|   |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                       |   |                                             |   |                         |   |   |   |       |   |      |
| 6005   |   | Pappenheim      32-34 |   | 0.9965            |   | 7N     |   | 54W    |   | 24     |   | SWNE   |   | 01/20/06       |   | 785600 |   | Ronald L. Pappenheim      and Betty J. Pappenheim |   | Petroleum      Development Corporation           |   | January 7,      2005    |   | -      |   | -          |   | 3271254   |

----

|   | Exhibit      "A"                                                                                                                                                                                             |   | Weld      County, Colorado |
|--------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|----------------------------|
|   | Attached to and made      part of that Assignment of Working      Interest dated July 14, 2006 by and betweenPetroleum Development      Corporation and Rockies Region Private Limited      Partnership |   |                       |

| AFE      # |   | WELL      NAME        |   | WORKING      INT. |   | TWP    |   | RNG    |   | SEC    |   | Q/Q    |   | SPUD      DATE |   | LEASES |   | LESSOR                                                                |   | LESSEE                                 |   | LEASE      DATE              |   | BOOK   |   | PACE   |   | RECEPTION |
|------------|--------|-----------------------|--------|-------------------|--------|--------|--------|--------|--------|--------|--------|--------|--------|----------------|--------|--------|--------|-----------------------------------------------------------------------|--------|----------------------------------------|--------|------------------------------|--------|--------|--------|--------|--------|-----------|
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |
| 6006       |   | Pappenheim      22-24 |   | 0.99B5            |   | 7N     |   | 64W    |   | 24     |   | SENW   |   | 01/25/06       |   | 785700 |   | Ronald L Pappenheim      and Betty J. Pappenheim  |   | Petroleum      Development Corporation |   | January 7,      2005    |   | -      |   | -      |   | 3271255   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 801700 |   | George W. Brewer,      Fr. And Wanda E. Brewer         |   | Petroleum      Development Corporation |   | January 7,      2005    |   | -      |   | -      |   | 3297103   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |   |   |   |      |
| 6007       |   | Pappenheim      12-24 |   | 0.9985            |   | 7N     |   | 64W    |   | 24     |   | SWNW   |   | 01/25/06       |   | 785700 |   | Ronald L. Pappenheim      and Betty J. Pappenheim |   | Petroleum      Development Corporation |   | January 7,2005          |   | -      |   | -      |   | 3271255   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 801700 |   | George W. Brewer,      Fr. And Wanda E. Brewer    |   | Petroleum      Development Corporation |   | January 7.2005          |   | -      |   | -      |   | 3297103   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |   |   |   |      |
| 6009       |   | Pappenheim      43-26 |   | 0.9985            |   | 7N     |   | 64W    |   | 26     |   | NESE   |   | 02/03/06       |   | 785100 |   | Ronald L Pappenheim      and Betty J. Pappenheim  |   | Petroleum      Development Corporation |   | January 7,      2005    |   | -      |   | -      |   | 3310621   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |   |   |   |      |
| 6008       |   | Pappenheim      33-26 |   | 0.9985            |   | 7N     |   | 64W    |   | 26     |   | NWSE   |   | 02/08/06       |   | 785100 |   | Ronald L. Pappenheim      and Betty J. Pappenheim |   | Petroleum      Development Corporation |   | January 7,      2005    |   | -      |   | -      |   | 3310621   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |   |   |   |      |
| 6020       |   | Hazen      13-28      |   | 0.9985            |   | 7N     |   | 65W    |   | 28     |   | NWSW   |   | 03/15/06       |   | 730400 |   | Gary Lynn Hazen      and Mary A. Hazen            |   | Petroleum      Development Corporation |   | September 30,      2003 |   | -      |   | -      |   | 3232682   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 800900 |   | Jerald B.      Winter and Margaret Jane Winter         |   | Petroleum      Development Corporation |   | April 20,      2005     |   | -      |   | -      |   | 3285892   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |   |   |   |      |
| 6021       |   | Hazen      24-28      |   | 0.9985            |   | 7N     |   | 65W    |   | 28     |   | SESW   |   | 03/19/06       |   | 730400 |   | Gary Lynn Hazen      and Mary A. Hazen            |   | Petroleum      Developmeni Corporation |   | September 30,      2003 |   | -      |   | -      |   | 3232682   |
| 6019       |   | Aim      42-33        |   | 0.9985            |   | 7N     |   | 65W    |   | 33     |   | SENE   |   | 03724/06       |   | 730700 |   | Cad      A. Aim and Josephine R. Aim                             |   | Petroleum      Development Corporation |   | November 5,      2003   |   | -      |   | -      |   | 3232683   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 730600 |   | Raymond A,      Aim and Victoria M. Aim                |   | Petroleum      Development Corporation |   | November 5,      2003   |   | -      |   | -      |   | 3232684   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |   |   |   |      |
| 6018       |   | Aim      41-33        |   | 0.9985            |   | 7N     |   | 65W    |   | 33     |   | NENE   |   | 03/30/06       |   | 730700 |   | Carl A. Aim      and Josephine R. Aim             |   | Petroleum      Development Corporation |   | November 5,      2003   |   | -      |   | -      |   | 3232683   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 730600 |   | Raymond A. Aim      and Victoria M. Aim           |   | Petroleum      Development Corporation |   | November 5,      2003   |   | -      |   | -      |   | 3232684   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 730500 |   | Wayne A. Aim      and Julie T. Aim                |   | Petroleum      Development Corporation |   | November 5.      2005   |   | -      |   | -      |   | 3232685   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |   |   |   |      |
| 6118       |   | Anderson      23-34   |   | 0.9985            |   | 7N     |   | 66W    |   | 34     |   | NESW   |   | 03/15/06       |   | 842900 |   | Don      Anderson, Inc.                                               |   | Petroleum      Development Corporation |   | November 27,      2005  |   | -      |   | -      |   | 3354265   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 845500 |   | Colleen G. Rossman                                          |   | Petroleum      Development Corporation |   | December 17,      2005  |   |   |   |   |   | 3362282   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 847600 |   | Richard E. Mulhern,      Jr. and Elizabeth Mulhern     |   | Petroleum      Development Corporalion |   | December 17,      2005  |   |   |   |   |   | 3371850   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |   |   |   |      |
| 6130       |   | Anderson      14-34   |   | 0.9985            |   | 7N     |   | 66W    |   | 34     |   | SWSW   |   | 03/26/06       |   | 842900 |   | Don      Anderson, Inc.                                               |   | Petroleum      Development Corporation |   | November 27,      2005  |   | -      |   | -      |   | 3354265   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 845500 |   | Colleen G. Rossman                                          |   | Petroleum      Development Corporation |   | December 17,      2005  |   | -      |   | -      |   | 3362282   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 847600 |   | Richard E. Mulhern,      Jr. and Elizabeth Mulhern     |   | Petroleum      Development Corporation |   | December 17,      2005  |   | -      |   | -      |   | 3371850   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   |   |   |                                                                  |   |                                   |   |                         |   |   |   |   |   |      |
| 6134       |   | Anderson      13-34   |   | 0.9985            |   | 7N     |   | 66W    |   | 34     |   | NWSW   |   | 03/30/06       |   | 842900 |   | Don      Anderson, Inc.                                               |   | Petroleum      Development Corporation |   | November 27,      2005  |   | -      |   | -      |   | 3354265   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 845500 |   | Colleen G. Rossman                                          |   | Petroleum      Development Corporation |   | December 17,      2005  |   | -      |   | -      |   | 3362282   |
|       |   |                  |   |              |   |   |   |   |   |   |   |   |   |           |   | 847600 |   | Richard E. Mulhern,      Jr. and Elizabeth Mulhern     |   | Petroleum      Development Corporation |   | December 17,      2005  |   | -      |   | -      |   | 3371850   |

----

----

|   | PETROLEUM      DEVELOPMENT CORPORATION |
|--------|----------------------------------------|
|   | A      Nevada Corporation              |
|   |                                   |
|   | BY:                                    | /s/      James P. Wason |
|   | James      P. Wason                    |
|   | Director      of Land                  |

| STATE      OF WELD      | ) |    |
|-------------------------|---|---------|
|                    | ) | TO-WIT: |
| COUNTY      OF COLORADO | ) |    |

|   |   | /s/      Libby A. Belair                                                                                                                         |
|--------|--------|--------------------------------------------------------------------------------------------------------------------------------------------------|
|        |   | Libby      BelairNotary      Public-      ColoradoCounty      of DenverMy      Commission expires: December 4,2008 |

----

|   | Attached      to and made part of that Assignment of Working interest dated July 14,      2006 by and between Petroleum Development Corporation and Rockies Region      Private Limited Partnership | Garfield      County, Colorado |
|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------|

| AFE#   |   | WELL      NAME       |   | WORKING      INT. |   | TWP    |   | RNG    |   | SEC    |   | Q/Q    |   | Spud      Date |   | LEASE      # |   | LESSOR                                        |   | LESSEE                                 |   | LEASE      DATE              |   | BOOK   |   | PAGE   |   | RECEPTION |
|--------|--------|----------------------|--------|-------------------|--------|--------|--------|--------|--------|--------|--------|--------|--------|----------------|--------|--------------|--------|-----------------------------------------------|--------|----------------------------------------|--------|------------------------------|--------|--------|--------|--------|--------|-----------|
|   |   |                 |   |              |   |   |   |   |   |   |   |   |   |           |   |         |   |                                          |   |                                   |   |                         |   |   |   |   |   |      |
| 6111   |   | Chevron      2C-4D   |   | 0.9985            |   | 6S     |   | 96W    |   | 4      |   | SWNW   |   | 03/30/06       |   | 687100       |   | Chevron      U.S.A., Inc.                     |   | Petroleum      Development Corporation |   | September 20,      2001 |   | 1447   |   | 563    |   | 623084    |
| 6001   |   | Chevron      2F-4D   |   | 0.9985            |   | 6S     |   | 96W    |   | 4      |   | SWNW   |   | 01/02/06       |   | 687100       |   | Chevron      U.S.A., Inc.                     |   | Petroleum      Development Corporation |   | September 20,      2001 |   | 1447   |   | 563    |   | 623084    |
| 6042   |   | Puckett 14C-31D |   | 0.9985            |   | 6S     |   | 96W    |   | 31     |   | NESW   |   | 38740          |   | 636800       |   | Puckett      Land Co., a Colorado Corporation |   | Petroleum      Development Corporation |   | November 15,      1999  |   | 1164   |   | 400    |   | 556562    |
| 6083   |   | Puckett 12D-31D |   | 0.9985            |   | 6S     |   | 96W    |   | 31     |   | NESW   |   | 38743          |   | 636800       |   | Puckett      Land Co., a Colorado Corporation |   | Petroleum      Development Corporation |   | November 15,1999        |   | 1164   |   | 400    |   | 556562    |
| 6043   |   | Puckett      13D-31D |   | 0.9985            |   | 6S     |   | 96W    |   | 31     |   | NESW   |   | 38757          |   | 636800       |   | Puckett      Land Co., a Colorado Corporation |   | Petroleum      Development Corporation |   | November 15,      1999  |   | 1164   |   | 400    |   | 556562    |
| 6084   |   | Puckett 12B-31D |   | 0-9985            |   | 6S     |   | 96W    |   | 31     |   | NESW   |   | 02/13/06       |   | 636800       |   | Puckett      Land Co., a Colorado Corporation |   | Petroleum      Development Corporation |   | November 15, 1999  |   | 1164   |   | 400    |   | 556562    |
| 6044   |   | Puckett      23C-31D |   | 0.9985            |   | 6S     |   | 96W    |   | 31     |   | NESW   |   | 02/23/06       |   | 636800       |   | Puckett      Land Co., a Colorado Corporation |   | Petroleum      Development Corporation |   | November 15, 1999  |   | 1164   |   | 400    |   | 556562    |
| 6085   |   | Puckett      22D-31D |   | 0.9985            |   | 6S     |   | 96W    |   | 31     |   | NESW   |   | 03/01/06       |   | 636800       |   | Puckett      Land Co., a Colorado Corporation |   | Petroleum      Development Corporation |   | November 15,      1999  |   | 1164   |   | 400    |   | 556562    |
| 6041   |   | Puckett      23D-31D |   | 0.9985            |   | 6S     |   | 96W    |   | 31     |   | NESW   |   | 03/08/06       |   | 636800       |   | Puckett      Land Co., a Colorado Corporation |   | Petroleum      Development Corporation |   | November 15,1999        |   | 1164   |   | 400    |   | 556552    |
| 6040   |   | Puckett 24C-31D |   | 0.9985            |   | 6S     |   | 96W    |   | 31     |   | NESW   |   | 03/20/06       |   | 636300       |   | Puckett      Land Co., a Colorado Corporation |   | Petroleum      Development Corporation |   | November 15,1999        |   | 1164   |   | 400    |   | 556562    |

|   | When      Recorded Please Return To:   |
|--------|----------------------------------------|
|   | Petroleum      Development Corporation |
|   | 1775      Sherman Street, Suite 3000   |
|   | Denver,      CO 80203             |
|   | Attn:      Jenni Muller           |

----

----

|   | PETROLEUM      DEVELOPMENT CORPORATION |
|--------|----------------------------------------|
|   | A      Nevada Corporation              |
|   |                                   |
|   | BY:                                    | /s/      James P. Wason |
|   | James      P. Wason                    |
|   | Director      of Land                  |

| STATE      OF WELD      | ) |    |
|-------------------------|---|---------|
|                    | ) | TO-WIT: |
| COUNTY      OF COLORADO | ) |    |

|   |   | /s/      Carrie Eggleston                                                                                                                            |
|--------|--------|------------------------------------------------------------------------------------------------------------------------------------------------------|
|        |   | Carrie      EgglestonNotary      Public-      ColoradoCounty      of DenverMy      Commission expires: October 12,2010 |

----

|   | Attached      to and made part of that Assignment of Working Interest dated July 14,      2006 by and between Petroleum Development Corporation and Rockies      Region Private Limited Partnership |   | Sweetwater      County, Wyoming |
|--------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|---------------------------------|

| AFE#   |   | WELL      NAME     |   | WORKING      INT. |   | TWP    |   | RNG    |   | SEC    |   | Q/Q    |   | Spud      Date |   | CONTRACT      # |   | LESSOR                                                     |   | LESSEE                                         |   | CONTRACT      DATE         |   | BOOK   |   | PAGE   |   | RECEPTION |
|--------|--------|--------------------|--------|-------------------|--------|--------|--------|--------|--------|--------|--------|--------|--------|----------------|--------|-----------------|--------|------------------------------------------------------------|--------|------------------------------------------------|--------|----------------------------|--------|--------|--------|--------|--------|-----------|
|   |   |               |   |              |   |   |   |   |   |   |   |   |   |           |   |            |   |                                                       |   |                                           |   |                       |   |   |   |   |   |      |
| 6119   |   | Anadarko      14-1 |   | 0.6985            |   | 20N    |   | 91W    |   | 1      |   | SWSW   |   | 02/17/06       |   | 803500          |   | Anadarko      Land Corp. & Anadarko E&P LP, Farmor |   | Petroleum      Development Corporation, Farmee |   | February 2,      2006 |   | NA     |   | NA     |   | NA        |

----