| 1 | Adeco Energy Corporation | Norman, OK 73071 | Oil & Gas Operator | Apr 2014 |
| 2 | Aggie Oil Company | Lakewood, CO 80226 | Oil & Gas Operator | May 2001 |
| 3 | Aguila Operating Company LLC | Edmond, OK 73013 | Oil & Gas Operator | Apr 2025 |
| 4 | Alexander Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 5 | Allen Oil & Gas LLC | Ardmore, OK 73401 | Oil Operator | Aug 2022 |
| 6 | Alpine Inc | Oklahoma City, OK 73134-2504 | Oil & Gas Operator | Feb 2024 |
| 7 | Alpine Oil & Gas Inc | Edmond, OK 73083-1264 | Oil & Gas Operator | Mar 2008 |
| 8 | Altman Energy, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jul 2025 |
| 9 | Alvarado 2014 LLC | Houston, TX 77027 | Oil & Gas Operator | Jul 2025 |
| 10 | American Natural Energy Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | Jan 2025 |
| 11 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 12 | Anadarko Minerals Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2025 |
| 13 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | May 2025 |
| 14 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Jul 2025 |
| 15 | Apache Energy Resources Corp | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 16 | Apex Minerals Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 1994 |
| 17 | Arbuckle Enterprises, Inc. | Edmond, OK 73083 | Oil & Gas Operator | Apr 2025 |
| 18 | Aries Operating LP | Houston, TX 77042 | Oil & Gas Operator | Jul 2025 |
| 19 | Armor Energy II LLC | Tulsa, OK 74145 | Oil & Gas Operator | May 2025 |
| 20 | Arrowhead Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | May 2025 |
| 21 | Ashland Exploration Inc | Houston, TX 77218 | Oil & Gas Operator | Nov 2000 |
| 22 | Assiduous Energy LLC | Edmond, OK 73034 | Oil & Gas Operator | May 2025 |
| 23 | Atchley Resources, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | May 2025 |
| 24 | Athan Inc | Edmond, OK 73013-6628 | Oil & Gas Operator | Apr 2025 |
| 25 | Atteberry Engineering | Edmond, OK 73013-6624 | Oil & Gas Operator | Mar 2008 |
| 26 | Avalanche Oil & Gas LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Jul 2025 |
| 27 | Aven Gas & Oil Inc | Oklahoma City, OK 73113-0491 | Oil & Gas Operator | Nov 2021 |
| 28 | Aw Hembree Co | Shawnee, OK 74802-1725 | Oil & Gas Operator | Apr 2025 |