| 1 | Bennett Petroleum Corporation | Denver, CO 80203 | Oil Operator | Jun 1985 |
| 2 | Bridwell Oil Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Nov 2024 |
| 3 | Chesapeake Operating, LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Nov 2024 |
| 4 | Chipcore LLC | Casper, WY 82601 | Oil & Gas Operator | Sep 2024 |
| 5 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 2024 |
| 6 | DJ Resources Inc | Bowie, TX 76230 | Oil & Gas Operator | Nov 2017 |
| 7 | Eme Wyoming LLC | Lakewood, CO 80401 | Oil & Gas Operator | Sep 2024 |
| 8 | Fidelity Exploration & Production Company | Denver, CO 80203 | Oil & Gas Operator | Oct 2024 |
| 9 | Getty Oil Company | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 10 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 11 | J-Bird Well Service Incorporated | Gillette, WY 82717 | Oil Operator | Sep 2024 |
| 12 | Kestrel Energy Inc | Lakewood, CO 80401 | Oil & Gas Operator | Jan 2008 |
| 13 | Mallon Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2005 |
| 14 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Sep 2024 |
| 15 | MCM Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2024 |
| 16 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 17 | Samson Oil & Gas USA Inc | Denver, CO 80202 | Oil & Gas Operator | Sep 2024 |
| 18 | Stanco Petroleum Inc | Kimball, NE 69145 | Oil & Gas Operator | Jul 1999 |
| 19 | Texaco Exploration & Prod | Midland, TX 79702 | Oil & Gas Operator | Aug 2002 |
| 20 | Timberline Energy Inc | Franklin, PA 16323-0269 | Oil & Gas Operator | Dec 2023 |
| 21 | Toco Corporation | | Oil & Gas Operator | Oct 1991 |
| 22 | Transworld Systems Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 2024 |
| 23 | Vanmark Jack | Torrington, WY 82240 | Oil Operator | Dec 1997 |