| 1 | A H & L Operating Company Inc | Norman, OK 73070-4084 | Oil & Gas Operator | Apr 2015 |
| 2 | Abarr Trust (The) | Oklahoma City, OK 73179 | Oil & Gas Operator | Mar 2025 |
| 3 | Abraxas Petroleum Corporation | San Antonio, TX 78259 | Oil & Gas Operator | Jun 2025 |
| 4 | Aei Production Company | Edmond, OK 73083 | Oil & Gas Operator | Mar 2014 |
| 5 | Aexco Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Mar 2025 |
| 6 | Aikman Brothers | Midland, TX 79705 | Oil & Gas Operator | Dec 2000 |
| 7 | Aikman Brothers, LLC | Amarillo, TX 79109 | Oil & Gas Operator | Jan 2025 |
| 8 | Aladdin Petroleum Corporation | Wichita, KS 67202 | Oil & Gas Operator | Jan 2021 |
| 9 | All Exploration LLC | Oklahoma City, OK 73120-7829 | Oil & Gas Operator | Feb 2025 |
| 10 | Altex Oil Corp | Breckenridge, CO 80424-1057 | Oil & Gas Operator | Dec 1999 |
| 11 | Altman Energy, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jun 2025 |
| 12 | American Warrior Inc | Garden City, KS 67846 | Oil & Gas Operator | Feb 2025 |
| 13 | Amsler Jerry & Denese | Enid, OK 73703-9300 | Oil & Gas Operator | Jul 2020 |
| 14 | An-Son Corporation | Oklahoma City, OK 73124 | Oil & Gas Operator | Jan 2006 |
| 15 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Jun 2025 |
| 16 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Mar 2025 |
| 17 | Angel Exploration Company | Oklahoma City, OK 73102-8868 | Oil & Gas Operator | Jan 2019 |
| 18 | Angel Exploration LLC | Oklahoma City, OK 73116-3603 | Oil & Gas Operator | Mar 2025 |
| 19 | Anson Company | Oklahoma City, OK 73124 | Oil & Gas Operator | Apr 2018 |
| 20 | Antioch Operating LLC | Dallas, TX 75206 | Oil & Gas Operator | Mar 2025 |
| 21 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Jun 2025 |
| 22 | Apc Operating Partnership LP | Tulsa, OK 74136-4224 | Oil & Gas Operator | Jun 2015 |
| 23 | Apollo Energies Inc | Pratt, KS 67124 | Oil & Gas Operator | Feb 2025 |
| 24 | Aquila Energy Resources Corp. | Houston, TX 77042 | Oil & Gas Operator | Nov 2013 |
| 25 | Arbor Petroleum Corporation | Oklahoma City, OK 73102-4003 | Oil & Gas Operator | Mar 2011 |
| 26 | Arbuckle Enterprises, Inc. | Edmond, OK 73083 | Oil & Gas Operator | Feb 2025 |
| 27 | Arrington CJM, Inc. | Canadian, TX 79014 | Oil & Gas Operator | Nov 2021 |
| 28 | Arrington Properties Inc | Edmond, OK 73034-3724 | Oil & Gas Operator | May 1996 |
| 29 | Arrowhead Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | Mar 2025 |
| 30 | Aspen Energy Group, Inc. | Santa Ynez, CA 93460 | Oil & Gas Operator | Mar 2015 |
| 31 | Atchley Resources, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Mar 2025 |
| 32 | Athena Energy, Inc. | Gallatin, TN 37066 | Oil & Gas Operator | Jun 2025 |
| 33 | Atlantic Richfield Company | Plano, TX 75074 | Oil & Gas Operator | Dec 2016 |
| 34 | Avalanche Oil & Gas LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Jun 2025 |
| 35 | Avalon Exploration Inc | Tulsa, OK 74119-5401 | Oil & Gas Operator | Dec 2019 |