| 1 | Amoco Production Company | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 2 | Baldwin Lynch Energy Corp. | Fort Collins, CO 80525-3354 | Oil Operator | Feb 2026 |
| 3 | Big Sky Energy, LLC | Cody, WY 82414 | Oil & Gas Operator | May 2024 |
| 4 | Bluebonnet Energy Corporation | Englewood, CO 80112 | Oil & Gas Operator | Sep 2015 |
| 5 | Contango Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 6 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 7 | Energy Corporation Of America | Charleston, WV 25311 | Oil & Gas Operator | Dec 2024 |
| 8 | Equity Oil Company | Salt Lake City, UT 84110-095 | Oil & Gas Operator | Aug 2004 |
| 9 | Genesis St Operating LLC | Kansas City, MO 64108 | Oil & Gas Operator | Apr 2026 |
| 10 | Grizzly Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Jan 2026 |
| 11 | Howell Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 2015 |
| 12 | KGH Operating Company | Billings, MT 59115 | Oil & Gas Operator | Feb 2026 |
| 13 | Luff Exploration Company | Denver, CO 80203 | Oil & Gas Operator | Feb 2026 |
| 14 | Macum Energy Inc | Billings, MT 59104 | Oil & Gas Operator | Aug 2021 |
| 15 | Midway Energy, LLC | Thermopolis, WY 82443 | Oil Operator | Jan 2026 |
| 16 | Montana Power Company | Butte, MT 59701 | Oil & Gas Operator | Apr 2002 |
| 17 | Montana Power Gas Company | | Oil & Gas Operator | Apr 2002 |
| 18 | Northwestern Corporation | Butte, MT 59701 | Oil & Gas Operator | Mar 2026 |
| 19 | Northwestern Energy, LLC | Butte, MT 59701 | Oil & Gas Operator | Dec 2004 |
| 20 | Petroleum Engineering & Management Corp. | Casper, WY 82609 | Oil & Gas Operator | Jul 2018 |
| 21 | Phoenix Production Company | Cody, WY 82414-3607 | Oil & Gas Operator | Oct 2023 |
| 22 | R3 Operating Corporation | Denver, CO 80222 | Oil & Gas Operator | Apr 2026 |
| 23 | Saga Petroleum, LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2018 |
| 24 | T2 Operating Corporation | Denver, CO 80202 | Oil & Gas Operator | Apr 2026 |
| 25 | Westech Energy Corporation | Denver, CO 80237 | Oil & Gas Operator | Mar 2011 |
| 26 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Apr 2026 |
| 27 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |