| 1 | Amoco Production Company | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 2 | Arp Production Company, LLC | Fort Worth, TX 76102 | Gas Operator | Jan 2026 |
| 3 | Black Warrior Methane Corp. | | Gas Operator | Jan 2026 |
| 4 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 5 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 6 | Energen Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Jan 2021 |
| 7 | Geomet Operating Co., Inc. | | Gas Operator | Dec 2013 |
| 8 | Kukui Operating Company | Ignacio, CO 81137 | Oil & Gas Operator | May 2013 |
| 9 | Oak Grove Resources, LLC | | Gas Operator | Aug 2025 |
| 10 | PGP Operating, LLC | Vance, AL 35490 | Gas Operator | Jan 2026 |
| 11 | Saga Petroleum Limited Liability Company Of Colorado | | Gas Operator | Dec 2014 |
| 12 | Saga Resource Management LLC | | Gas Operator | Jan 2026 |
| 13 | Taurus Exploration, Inc. | | Oil & Gas Operator | Jan 2026 |
| 14 | U.S. Steel Mining Co., Inc. | | Gas Operator | Jan 2000 |
| 15 | U.S. Steel Mining Co., LLC | | Gas Operator | Oct 2002 |