| 1 | Capitol Oil & Gas Corporation | Centennial, WY 82055 | Oil Operator | Feb 2006 |
| 2 | Carol-Holly Oil Corporation | Denver, CO 80237 | Oil & Gas Operator | Aug 2025 |
| 3 | Celsius Energy Company | Denver, CO 80202-1558 | Oil & Gas Operator | Mar 2000 |
| 4 | Cenergy Resources LLC | | Oil & Gas Operator | Jul 2025 |
| 5 | Central Resources Inc | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 6 | Central Wyoming Resources LTD | Glenrock, WY 82637 | Oil Operator | Jul 2021 |
| 7 | Century Production Inc | | Oil & Gas Operator | Dec 1986 |
| 8 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Aug 2025 |
| 9 | Chambers Jerry | Denver, CO 80237 | Oil & Gas Operator | Dec 1993 |
| 10 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 11 | Chaparral Resources Inc | Denver, CO 80293 | Oil & Gas Operator | Jan 1996 |
| 12 | Chapman Exploration Inc | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2013 |
| 13 | Charger Resources, LLC | Hurst, TX 76054 | Oil & Gas Operator | Aug 2015 |
| 14 | Chemily Management Company | Cypress, TX 77429 | Oil & Gas Operator | Apr 2023 |
| 15 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Oct 2025 |
| 16 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 17 | Chipcore LLC | Casper, WY 82601 | Oil & Gas Operator | Aug 2025 |
| 18 | Chippewa Oil & Gas Inc | Douglas, WY 82633 | Oil & Gas Operator | Jan 1985 |
| 19 | Chriscor Oil & Gas | Plana, TX 75075 | Oil & Gas Operator | Jul 1987 |
| 20 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Oct 2025 |
| 21 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 22 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 23 | Coleman Oil & Gas Inc | Farmington, NM 87499 | Oil & Gas Operator | Jan 2023 |
| 24 | Colorado Oil & Gas Corporation | | Oil & Gas Operator | May 2003 |
| 25 | Combined Oil & Gas | Denver, CO 80202 | Oil & Gas Operator | Feb 1990 |
| 26 | Comet Energy Services LLC | Traverse City, MI 49686 | Oil & Gas Operator | Oct 2011 |
| 27 | Common Energy Inc | Douglas, WY 82633 | Oil & Gas Operator | Aug 1995 |
| 28 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 29 | Conquest Exploration | Houston, TX 77068 | Oil & Gas Operator | May 1991 |
| 30 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 31 | Continental Industries LC | Casper, WY 82602 | Oil & Gas Operator | Feb 2008 |
| 32 | Continental Production Co LLC | Greenwood VIllage, CO 80155 | Oil & Gas Operator | Aug 2012 |
| 33 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Oct 2025 |
| 34 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 35 | Cook D L | Holliday, TX 76366 | Oil & Gas Operator | Dec 2008 |
| 36 | Coquina Oil Corporation | Houston, TX 77227 | Oil & Gas Operator | Mar 2015 |
| 37 | Corrida Oil Inc | Denver, CO 80217 | Oil & Gas Operator | Jun 1990 |
| 38 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 39 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 40 | Creek Oil Company | Colorado Springs, CO 80906 | Oil & Gas Operator | Aug 2001 |