| 1 | C. V. Radke | | Oil Operator | Jan 1993 |
| 2 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Jun 2025 |
| 3 | Caddo Management, Inc | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 4 | Cajun Minerals, Inc. | | Oil & Gas Operator | Mar 1997 |
| 5 | Cajun Operating, Inc. | | Oil & Gas Operator | Jun 2011 |
| 6 | Callon Offshore Production, Inc. | Natchez, MS 39121 | Oil & Gas Operator | Dec 2005 |
| 7 | Callon Petroleum Company | Natchez, MS 39120 | Oil & Gas Operator | Jan 2000 |
| 8 | Callon Petroleum Operating Co | Houston, TX 77042 | Oil & Gas Operator | Jul 2024 |
| 9 | Camex Operating Company | | Oil & Gas Operator | Dec 2024 |
| 10 | Camex, Inc. | | Oil & Gas Operator | Jun 1992 |
| 11 | Cardinal Oil & Gas, Inc. | | Oil & Gas Operator | Jun 1995 |
| 12 | Carl E. Hansford | | Oil Operator | Oct 1980 |
| 13 | Carl Oil & Gas Co. | Bakersfield, CA 93309 | Oil & Gas Operator | Dec 1995 |
| 14 | Carrollton Resources Corp. | | Oil & Gas Operator | Sep 2000 |
| 15 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 16 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 17 | Cayman Exploration Corp. | Tulsa, OK 74119-1323 | Oil & Gas Operator | Jun 2001 |
| 18 | Celeron Oil & Gas Company | | Oil & Gas Operator | Dec 1987 |
| 19 | Century Mineral Corporation | | Oil & Gas Operator | Dec 1990 |
| 20 | Chambers Exploration Inc. | | Oil & Gas Operator | Dec 1986 |
| 21 | Champlin Petroleum Co. | Rock Springs, WY 82902 | Oil & Gas Operator | Mar 1991 |
| 22 | Charles Holston, Inc. | | Oil Operator | Jan 2025 |
| 23 | Charles Holston, Inc. Dba GTTS | | Oil Operator | Apr 2009 |
| 24 | Cheniere Petroleum Corporation | | Oil & Gas Operator | Feb 1989 |
| 25 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 26 | Christopher Oil & Gas Inc | Fulshear, TX 77441 | Oil & Gas Operator | Apr 2015 |
| 27 | Chroma Operating, Inc. | Washington, DC 20036 | Oil & Gas Operator | Jun 2016 |
| 28 | Cibco Resources, LLC | | Oil & Gas Operator | Nov 2024 |
| 29 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Oct 2025 |
| 30 | Cities Service Company | | Oil & Gas Operator | Mar 1983 |
| 31 | Cities Service Oil & Gas Corp | | Oil & Gas Operator | Mar 1988 |
| 32 | Cities Service Oil Co. | | Oil & Gas Operator | Dec 1986 |
| 33 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 34 | Clearly Petroleum, LLC | Houston, TX 77086 | Oil & Gas Operator | Jun 2020 |
| 35 | Cliffwood Production Co. | Houston, TX 77090 | Oil & Gas Operator | Aug 2013 |
| 36 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 37 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 38 | Coastal Production Inc. | | Oil & Gas Operator | Aug 2000 |
| 39 | Cody Energy LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2020 |
| 40 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Aug 2025 |
| 41 | Collet Oil Ventures, Inc. | Denver, CO 80217 | Oil & Gas Operator | Jun 2004 |
| 42 | Columbia Gulf Transmission Co. | | Oil Operator | Dec 2014 |
| 43 | Columbia Gulf Transmission Company, LLC | | Oil Operator | Jan 2025 |
| 44 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 45 | Consolidated Resources Inc | | Oil & Gas Operator | May 2004 |
| 46 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 47 | Coronado Energy E&P Company, LLC | Houston, TX 77252 | Oil & Gas Operator | Dec 2010 |
| 48 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 49 | Cougar Exploration, Inc. | | Oil & Gas Operator | Jun 1988 |
| 50 | Cox Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2014 |
| 51 | Crab Run Gas Company | | Oil & Gas Operator | Feb 1982 |
| 52 | Crain & Dore Production Co Inc | | Oil & Gas Operator | Oct 1990 |
| 53 | Credo Petroleum Corporation | Denver, CO 80202 | Oil & Gas Operator | Jan 2013 |
| 54 | Crescent DRLG & DVLPMNT, Inc. | | Oil & Gas Operator | Oct 1992 |
| 55 | Crosstex Lig, LLC | | Oil Operator | Mar 2014 |
| 56 | Crown Central Petroleum Corp | Richmond, TX 77469 | Oil & Gas Operator | Dec 1999 |
| 57 | Crystal Oil And Land Company | | Oil & Gas Operator | May 1992 |
| 58 | Cummins & Walker Oil Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2021 |
| 59 | CX Operating, Inc. | | Oil & Gas Operator | Oct 2023 |
| 60 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |
| 61 | Cypress Oil Company, Inc. | | Oil & Gas Operator | Aug 2003 |
| 62 | Cypress Production, Inc. | Azle, TX 76020 | Oil & Gas Operator | Oct 2025 |