| 1 | C & K Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1984 |
| 2 | C & VC, Inc. | | Oil & Gas Operator | Sep 1991 |
| 3 | C&M Operating Company, LLC | | Oil & Gas Operator | Apr 2011 |
| 4 | C.F. Braun & Company | | Oil & Gas Operator | Dec 1986 |
| 5 | C.F.D. Inc. | | Oil & Gas Operator | Nov 1988 |
| 6 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Jun 2025 |
| 7 | Caddo Management, Inc | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 8 | Callon Offshore Production, Inc. | Natchez, MS 39121 | Oil & Gas Operator | Dec 2005 |
| 9 | Cambridge Energy Corporation | | Oil & Gas Operator | Jul 2003 |
| 10 | Caribbean Oil & Gas Corp | | Oil & Gas Operator | Mar 1980 |
| 11 | Carl Oil & Gas Co. | Bakersfield, CA 93309 | Oil & Gas Operator | Dec 1995 |
| 12 | Carlson Petroleum Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 13 | Carrollton Resources Corp. | | Oil & Gas Operator | Sep 2000 |
| 14 | Caruthers Producing Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2019 |
| 15 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 16 | Castlerock Oil Company, Inc. | Addison, TX 75001 | Oil & Gas Operator | Feb 2006 |
| 17 | Caza Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 18 | Cei Production Company | Dallas, TX 75225 | Oil & Gas Operator | Sep 1998 |
| 19 | Cel Properties LLC | | Oil & Gas Operator | Jan 2025 |
| 20 | Celeron Oil & Gas Company | | Oil & Gas Operator | Dec 1987 |
| 21 | Central Resources Inc | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 22 | Centurion Exploration Company | Houston, TX 77042 | Oil & Gas Operator | May 2009 |
| 23 | Chaparral Energy, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Dec 2009 |
| 24 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 25 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 26 | Chroma Operating, Inc. | Washington, DC 20036 | Oil & Gas Operator | Jun 2016 |
| 27 | Cimarex Energy Co. | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 28 | Cities Service Oil Co. | | Oil & Gas Operator | Dec 1986 |
| 29 | Clark Oil Producing Company | | Oil & Gas Operator | Oct 1979 |
| 30 | CMS Nomeco Oil & Gas Co. | Jackson, MI 49201 | Oil & Gas Operator | Jan 2015 |
| 31 | CMS Oil And Gas Company | Jackson, MI 49201 | Oil & Gas Operator | Oct 2002 |
| 32 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 33 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 34 | Coastal States & Emerald Oil | | Oil & Gas Operator | Dec 1979 |
| 35 | Comstock Offshore, LLC | | Oil & Gas Operator | Nov 2004 |
| 36 | Comstock Oil & Gas -- La, Inc. | | Oil & Gas Operator | Mar 2005 |
| 37 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 38 | Contango Operators, Inc. | Houston, TX 77098 | Oil & Gas Operator | Dec 2022 |
| 39 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 40 | Contour Energy E & P, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2002 |
| 41 | Contour Energy E & P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2003 |
| 42 | Corpus Christi Oil & Gas Co. | | Oil & Gas Operator | Dec 1991 |
| 43 | Corum Production Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 44 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 45 | Cox Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2014 |
| 46 | Crosstex Lig, LLC | | Oil Operator | Mar 2014 |
| 47 | Crystal Oil Company | Shreveport, LA 71120 | Oil & Gas Operator | Jul 1995 |