| 101 | Cheyenne Petroleum Company | Oklahoma City, OK 73134 | Oil & Gas Operator | May 2025 |
| 102 | Chisholm Oil & Gas, LC | Buda, TX 78610 | Oil & Gas Operator | May 2025 |
| 103 | Choice Exploration, Inc. | Irving, TX 75063 | Oil & Gas Operator | May 2025 |
| 104 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 105 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | May 2025 |
| 106 | Cimarron Engineering Corp. | Kingsville, TX 78364 | Oil & Gas Operator | May 2015 |
| 107 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | May 2025 |
| 108 | Clay Exploration, Inc. | Spring, TX 77387 | Oil & Gas Operator | Jun 2019 |
| 109 | Clearly Petroleum, LLC | Houston, TX 77086 | Oil & Gas Operator | Jun 2020 |
| 110 | Clide Oil Corp. | Iraan, TX 79744 | Oil & Gas Operator | Nov 2015 |
| 111 | CLR Secondary Recovery, LLC | Wichita Falls, TX 76306 | Oil & Gas Operator | May 2025 |
| 112 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 113 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 114 | Coastland Operations, LLC | Dallas, TX 75287 | Oil & Gas Operator | May 2025 |
| 115 | Coastline Exploration, Inc. | Stafford, TX 77477 | Oil & Gas Operator | May 2025 |
| 116 | Coastline Operating, L.L.C. | Houston, TX 77027 | Oil & Gas Operator | Dec 2006 |
| 117 | Collins & Ware, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 118 | Collins Resources, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Mar 2011 |
| 119 | Columbia Gas Development Corp. | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 120 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 121 | Comstock Oil & Gas, Inc. | Frisco, TX 75034 | Oil & Gas Operator | Dec 2012 |
| 122 | Comstock Oil & Gas, LP | Frisco, TX 75034 | Oil & Gas Operator | Aug 2019 |
| 123 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 124 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 125 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 126 | Cordillera Texas, L.P. | Greenwood VLG, CO 80111 | Oil & Gas Operator | Sep 2008 |
| 127 | Coronado Energy E&P Company, LLC | Houston, TX 77252 | Oil & Gas Operator | Dec 2010 |
| 128 | Corum Production Company | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 129 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 130 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 131 | Cotton Valley Resources, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2025 |
| 132 | Cox & Perkins Exploration, Inc. | Houston, TX 77057 | Oil & Gas Operator | May 2025 |
| 133 | Crawford Energy Operating Co | Houston, TX 77056 | Oil & Gas Operator | Aug 2008 |
| 134 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 135 | Crest Resources & Expl. Corp. | Houston, TX 77079 | Oil & Gas Operator | Dec 1998 |
| 136 | Crest Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 137 | Cxy Energy, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Nov 2000 |
| 138 | Cyber Enviro-Tech Inc | | Oil & Gas Operator | May 2025 |
| 139 | Cypress Production, Inc. | Azle, TX 76020 | Oil & Gas Operator | May 2025 |
| 140 | D & T Company | Denver, CO 80210 | Oil & Gas Operator | Jun 1983 |
| 141 | Dale Operating Company | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 142 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 143 | Dallas Petroleum Group, LLC | Dallas, TX 75379 | Oil & Gas Operator | May 2025 |
| 144 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 145 | Dan A. Hughes Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | Feb 2025 |
| 146 | Dantex Oil & Gas, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 147 | Davis Bros. Oil Producers, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2020 |
| 148 | Davis Gulf Coast, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 149 | Deep Rock Resources, Inc. | Dallas, TX 75206 | Oil & Gas Operator | May 2025 |
| 150 | Deguello Operating LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 151 | Dekalb Energy Company | Oklahoma City, OK 73134 | Oil & Gas Operator | Oct 1996 |
| 152 | Delta Exploration Company Inc | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 153 | Denali Oil & Gas Management, LLC | Houston, TX 77060 | Oil & Gas Operator | Dec 2012 |
| 154 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2025 |
| 155 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 156 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 157 | DJ Exploration, Inc. | San Antonio, TX 78257 | Oil & Gas Operator | May 2025 |
| 158 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 159 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 160 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 161 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | May 2025 |
| 162 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 163 | Drillmar Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | Nov 2014 |
| 164 | Drillmar Operating Company | Houston, TX 77019 | Oil & Gas Operator | Jun 2013 |
| 165 | Dynamic Production, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | May 2025 |
| 166 | Eagle Energy Development Co | La Porte, TX 77571 | Oil & Gas Operator | Dec 2024 |
| 167 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | May 2025 |
| 168 | Earthstone Energy, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2017 |
| 169 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 170 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | May 2025 |
| 171 | Elk Energy Holdings LLC | Wichita, KS 67226 | Oil & Gas Operator | Jan 2025 |
| 172 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 173 | Elliott Oil & Gas Operating Co. | Magnolia, TX 77354 | Oil & Gas Operator | May 2025 |
| 174 | Enercorp Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 1993 |
| 175 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 176 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | Jan 2025 |
| 177 | Engelke, R. H. | San Antonio, TX 78230 | Oil & Gas Operator | May 2025 |
| 178 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 179 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 180 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 181 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | May 2022 |
| 182 | EP Operating Limited Partnership | Dallas, TX 75201 | Oil & Gas Operator | Feb 1995 |
| 183 | Erskine Energy, LLC | H SPG NTL PK, AR 71909 | Oil & Gas Operator | May 2025 |
| 184 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Feb 2025 |
| 185 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 186 | Etoco Incorporated | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 187 | Exotic Oil & Gas LLC | Indiana, PA 15701-3634 | Oil & Gas Operator | Dec 2024 |
| 188 | Expro Engineering, Inc. | Fort Worth, TX 76179 | Oil & Gas Operator | May 2025 |
| 189 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 190 | F.I.G. Energy, LLC | Livingston, TX 77399 | Oil & Gas Operator | May 2025 |
| 191 | Famcor Oil, Inc. | Scottsdale, AZ 85260 | Oil & Gas Operator | Sep 2020 |
| 192 | Fergus Oil & Gas, LLC | Allen, TX 75013 | Oil Operator | May 2025 |
| 193 | Field Petroleum Corp. | San Antonio, TX 78216 | Oil & Gas Operator | May 2025 |
| 194 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 195 | Finley Resources Inc | Fort Worth, TX 76113 | Oil & Gas Operator | May 2025 |
| 196 | First Aransas Reserves, Inc. | Alvin, TX 77511 | Oil & Gas Operator | Mar 2018 |
| 197 | Five-Jab, Inc. | Tomball, TX 77377 | Oil & Gas Operator | May 2025 |
| 198 | Fletcher Operating, LLC | Fairhope, AL 36532 | Oil & Gas Operator | May 2025 |
| 199 | Forbes, C. C. Company | Alice, TX 78333 | Oil & Gas Operator | Sep 2015 |
| 200 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |