| 1 | A & A Tank Truck Company | Norman, OK 73070-8969 | Oil & Gas Operator | Jul 2025 |
| 2 | A H & L Operating Company Inc | Norman, OK 73070-4084 | Oil & Gas Operator | Apr 2015 |
| 3 | Alexander Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 4 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 5 | Antero Resources Corporation | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 6 | Arapahoe Resources LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Jun 2025 |
| 7 | Arbor Petroleum Corporation | Oklahoma City, OK 73102-4003 | Oil & Gas Operator | Mar 2011 |
| 8 | Archibald Oil & Gas Operating Inc | Ada, OK 74820 | Oil & Gas Operator | Jun 2025 |
| 9 | Aries Operating LP | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 10 | Arkla Energy Resources | Shreveport, LA 71151 | Oil & Gas Operator | Mar 2015 |
| 11 | Arkoma Holding Corporation | Oklahoma City, OK 73102-5684 | Gas Operator | Jul 2007 |
| 12 | Arkoma Resources LLC | Henryetta, OK 74437 | Oil & Gas Operator | Jul 2025 |
| 13 | Arrow Energy, Incorporated | Houston, TX 77008 | Oil & Gas Operator | Jun 2025 |
| 14 | Arrow Operating Company | Dallas, TX 75231 | Oil & Gas Operator | Jun 2025 |
| 15 | Aspen Energy Group, Inc. | Santa Ynez, CA 93460 | Oil & Gas Operator | Mar 2015 |
| 16 | Atlantic Richfield Company | Plano, TX 75074 | Oil & Gas Operator | Dec 2016 |