| 2001 | Casco Energy, Inc. | Denison, TX 75020 | Oil & Gas Operator | May 1996 |
| 2002 | Case Oil | Burkburnett, TX 76354 | Oil & Gas Operator | Feb 2026 |
| 2003 | Case Resources, LLC | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 2004 | Case, C. W. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 2005 | Casey, W. J. | Fairfield, TX 75840 | Oil & Gas Operator | Feb 2026 |
| 2006 | Cashco Oil Company | Houston, TX 77024 | Oil & Gas Operator | Aug 2003 |
| 2007 | Cashco, L.L.C. | Houston, TX 77024 | Oil & Gas Operator | Jul 1999 |
| 2008 | Cashion, Lyle, Company | Brandon, MS 39047 | Oil & Gas Operator | May 2008 |
| 2009 | Casias Oil Well Service, Inc. | San Antonio, TX 78232 | Oil & Gas Operator | Jul 2020 |
| 2010 | Casillas Petroleum Corp | Satanta, KS 67870 | Oil & Gas Operator | Dec 2025 |
| 2011 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Feb 2026 |
| 2012 | Caspen Oil, Inc. | Denver, CO 80226 | Oil & Gas Operator | Jul 1993 |
| 2013 | Caspen Operating Company | Somerset, TX 78069 | Oil & Gas Operator | Mar 2008 |
| 2014 | Casper Oil & Gas | Bandera, TX 78003 | Oil & Gas Operator | Oct 2002 |
| 2015 | Cass Energy Corp | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 2016 | Cass Energy LLC | MT Vernon, TX 75457 | Oil Operator | Feb 2026 |
| 2017 | Cassity Company | Wichita Falls, TX 76309 | Oil & Gas Operator | Jul 2013 |
| 2018 | Casteel, Hoyt F. | Graham, TX 76450 | Oil & Gas Operator | Nov 2001 |
| 2019 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 2020 | Castillo Oil Company LLC | Luling, TX 78648 | Oil & Gas Operator | Feb 2026 |
| 2021 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 2022 | Castle Gas Corporation | San Angelo, TX 76902 | Oil & Gas Operator | Oct 2014 |
| 2023 | Castle Operating LLC | Oklahoma City, OK 73114-7444 | Oil & Gas Operator | Nov 2025 |
| 2024 | Castle Production Company | Henderson, TX 75652 | Oil & Gas Operator | May 1997 |
| 2025 | Castlerock Ef Operating LLC | San Antonio, TX 78232 | Oil & Gas Operator | Feb 2026 |
| 2026 | Castlerock Oil Company, Inc. | Addison, TX 75001 | Oil & Gas Operator | Feb 2006 |
| 2027 | Castlerock Operating, LLC | San Antonio, TX 78232 | Oil & Gas Operator | Dec 2020 |
| 2028 | Caswell Bros. Oil Co. | Bowie, TX 76230 | Oil & Gas Operator | Feb 2026 |
| 2029 | Catarina Petroleum L. C. | Dallas, TX 75228 | Oil & Gas Operator | Jun 2008 |
| 2030 | Catfish Minerals LLC | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 2031 | Cathexis Oil & Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2014 |
| 2032 | Cathey Petroleum Company, Inc. | Big Spring, TX 79720 | Oil & Gas Operator | Apr 2008 |
| 2033 | Caths Oil & Gas | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 2034 | Catlin Drilling Company | Iowa Park, TX 76367 | Oil & Gas Operator | Aug 2003 |
| 2035 | Catlin, Carl | Jacksboro, TX 76458 | Oil & Gas Operator | Mar 2008 |
| 2036 | Catlin, Cecil | Iowa Park, TX 76367 | Oil & Gas Operator | Dec 1995 |
| 2037 | Catlin, Cecil, Oil Co. | Iowa Park, TX 76367 | Oil & Gas Operator | Jun 2000 |
| 2038 | Catlin, Delbert | Iowa Park, TX 76367 | Oil & Gas Operator | Feb 2026 |
| 2039 | Catlin, Randy | Iowa Park, TX 76367 | Oil Operator | Feb 2026 |
| 2040 | Catoilan Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 2041 | Caturus Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Feb 2026 |
| 2042 | Cavalcade Operating Company LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2017 |
| 2043 | Cavalier Oil & Gas, Inc. | Buchanan Dam, TX 78609 | Oil & Gas Operator | Feb 2026 |
| 2044 | Cavalry Resources LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2010 |
| 2045 | Cavilla Energy, Inc. | Longview, TX 75606 | Oil Operator | Feb 2026 |
| 2046 | Cavillo Oil Company LC Of Texas | Marshall, TX 75671 | Oil & Gas Operator | Feb 2026 |
| 2047 | Cavillo Oil Corporation | Marshall, TX 75670 | Oil & Gas Operator | Jun 1998 |
| 2048 | Cawell Energy, LLC | Spring, TX 77379 | Oil Operator | Feb 2026 |
| 2049 | Caza Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 2050 | Cazador Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 2051 | Cazar Energy Inc | Austin, TX 78734 | Oil & Gas Operator | Feb 2026 |
| 2052 | CB Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Nov 2017 |
| 2053 | CBM Partners Corporation | Overland Park, KS 66221 | Oil Operator | Aug 2015 |
| 2054 | Cbmoncrief Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |
| 2055 | CBN Operating Corp. | Austin, TX 78746 | Oil & Gas Operator | Feb 2026 |
| 2056 | CBR Oil Company | Lytle, TX 78052 | Oil & Gas Operator | Jul 1997 |
| 2057 | CCF, Inc. | Snyder, TX 79550 | Oil & Gas Operator | Apr 1998 |
| 2058 | CCGM Exploration & Prod.,L.C. | Austin, TX 78738 | Oil & Gas Operator | Feb 2026 |
| 2059 | Cci East Texas Upstream LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2021 |
| 2060 | Cci Gulf Coast Upstream LLC | Teague, TX 75860 | Oil & Gas Operator | Mar 2021 |
| 2061 | CCV, Inc. | Houston, TX 77019 | Oil & Gas Operator | Sep 1994 |
| 2062 | CD Consulting & Operating Co. | Bridgeport, TX 76426 | Oil & Gas Operator | Feb 2026 |
| 2063 | CD Resources Company | San Antonio, TX 78217 | Oil & Gas Operator | Mar 2002 |
| 2064 | CDC Operating Company | Dallas, TX 75218 | Oil & Gas Operator | Feb 2026 |
| 2065 | CDJ Oil Co. | Albany, TX 76430 | Oil & Gas Operator | Jul 2025 |
| 2066 | CDJ Oil Company, LLC | Albany, TX 76430 | Oil & Gas Operator | Feb 2026 |
| 2067 | CDX Gas, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2009 |
| 2068 | Cedar Bend Oil Company | Colorado City, TX 79512 | Oil & Gas Operator | Feb 2026 |
| 2069 | Cedar Oil Company | Midland, TX 79707 | Oil & Gas Operator | Feb 2026 |
| 2070 | Cedar Point Oil Company | Baytown, TX 77520 | Oil & Gas Operator | Aug 2003 |
| 2071 | Cedar Ridge Energy, Inc. | Coleman, TX 76834 | Oil & Gas Operator | Feb 2026 |
| 2072 | Cedyco Corporation | Houston, TX 77227 | Oil & Gas Operator | Nov 2008 |
| 2073 | Cegx Of Texas LLC | Eastland, TX 76448 | Oil Operator | Mar 2018 |
| 2074 | Cei Operating LLC | Katy, TX 77449 | Oil & Gas Operator | Feb 2026 |
| 2075 | Cei Production Company | Dallas, TX 75225 | Oil & Gas Operator | Sep 1998 |
| 2076 | Ceja Corporation | Tulsa, OK 74172 | Oil & Gas Operator | Dec 2025 |
| 2077 | Celero Energy II, LP | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 2078 | Celero Energy LP | Midland, TX 79701 | Oil & Gas Operator | May 2011 |
| 2079 | Cemco Oil | Corsicana, TX 75110 | Oil & Gas Operator | Feb 2026 |
| 2080 | Ceniza Petroleum, Inc. | Portland, TX 78374 | Oil & Gas Operator | Feb 2026 |
| 2081 | Centaur Exploration LLC | Evanston, WY 82931 | Oil & Gas Operator | Feb 2026 |
| 2082 | Centaur Petroleum Corporation | Fort Worth, TX 76101 | Oil & Gas Operator | Feb 2026 |
| 2083 | Centennial Energy Corp. | Big Lake, TX 76932 | Oil & Gas Operator | Jan 1997 |
| 2084 | Centennial Resource Prod, LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2023 |
| 2085 | Center Start, LC | Kilgore, TX 75663 | Oil & Gas Operator | May 2008 |
| 2086 | Centerfire Resources | Springerville, AZ 85938 | Oil & Gas Operator | Feb 2026 |
| 2087 | Centex Development | Giddings, TX 78942 | Oil & Gas Operator | Feb 2026 |
| 2088 | Centex Energy, LLC | Bryan, TX 77802 | Oil & Gas Operator | Feb 2026 |
| 2089 | Centex Pipe & Equipment, Inc. | Luling, TX 78648 | Oil & Gas Operator | Feb 2026 |
| 2090 | Central Basin Oil Inv. Inc. | Southlake, TX 76092 | Oil & Gas Operator | Feb 2026 |
| 2091 | Central Crude Corp. | Wichita, KS 67206 | Oil Operator | Mar 2014 |
| 2092 | Central Drilling Company, USA | Midland, TX 79710 | Oil & Gas Operator | May 2006 |
| 2093 | Central Energy Producing Company | San Antonio, TX 78217 | Oil & Gas Operator | Sep 2003 |
| 2094 | Central Gulf Petroleum Inc | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2026 |
| 2095 | Central Mineral Operating Co,Inc | San Antonio, TX 78216 | Oil & Gas Operator | Apr 1997 |
| 2096 | Central Plains Oil&Gas Corp. (A) | Bryan, TX 77802 | Oil & Gas Operator | Mar 2003 |
| 2097 | Central Resources, Inc. | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 2098 | Central Texas Operating, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2026 |
| 2099 | Centurion Exploration Company | Houston, TX 77042 | Oil & Gas Operator | May 2009 |
| 2100 | Centurion Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Jul 2009 |