| 101 | Calpine Natural Gas Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2002 |
| 102 | Cameron, Paul E., Jr., Inc. | Montgomery, TX 77356 | Oil & Gas Operator | May 2015 |
| 103 | Camoil, Inc. | Columbus, TX 78934 | Oil & Gas Operator | Mar 2025 |
| 104 | Capital Star Oil & Gas, Inc. | Houston, TX 77027 | Oil & Gas Operator | Mar 2025 |
| 105 | Carrizo Oil & Gas, Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 106 | Carter E&P, LLC | Johnson City, TX 78636 | Oil & Gas Operator | Dec 2016 |
| 107 | Carter Exploration Company | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Feb 2015 |
| 108 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Mar 2025 |
| 109 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 110 | CB Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Nov 2017 |
| 111 | Ceniza Petroleum, Inc. | Portland, TX 78374 | Oil & Gas Operator | Mar 2025 |
| 112 | Central Gulf Petroleum Inc | The Woodlands, TX 77380 | Oil & Gas Operator | Mar 2025 |
| 113 | Cet Energy Corporation | Spring, TX 77391 | Oil & Gas Operator | Nov 2003 |
| 114 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2025 |
| 115 | Charro Operating, L.L.C. | Englewood, CO 80112 | Oil & Gas Operator | Mar 2025 |
| 116 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2025 |
| 117 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Nov 2024 |
| 118 | Chevron Midcontinent, L.P. | Midland, TX 79706 | Oil & Gas Operator | Mar 2025 |
| 119 | Choice Exploration, Inc. | Irving, TX 75063 | Oil & Gas Operator | Mar 2025 |
| 120 | CHP Oil & Gas Company, L.C. | El Campo, TX 77437 | Oil & Gas Operator | Mar 2025 |
| 121 | Christeve Oil Company, Inc. | Houston, TX 77068 | Oil & Gas Operator | Dec 2022 |
| 122 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 123 | Cimarron Engineering Corp. | Kingsville, TX 78364 | Oil & Gas Operator | May 2015 |
| 124 | Clay Exploration, Inc. | Spring, TX 77387 | Oil & Gas Operator | Jun 2019 |
| 125 | Cliffwood Production Co. | Houston, TX 77090 | Oil & Gas Operator | Aug 2013 |
| 126 | CML Exploration, LLC | Austin, TX 78746 | Oil & Gas Operator | Mar 2025 |
| 127 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 128 | Coastal Investments Inc. | El Campo, TX 77437 | Oil & Gas Operator | Mar 2025 |
| 129 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 130 | Coastal Plains Exploration, LLC | Port Lavaca, TX 77979 | Oil & Gas Operator | Mar 2025 |
| 131 | Coastal Production Company, Inc. | El Campo, TX 77437 | Oil & Gas Operator | Aug 1995 |
| 132 | Coastline Exploration, Inc. | Stafford, TX 77477 | Oil & Gas Operator | Mar 2025 |
| 133 | Coastline Operating, L.L.C. | Houston, TX 77027 | Oil & Gas Operator | Dec 2006 |
| 134 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Jan 2025 |
| 135 | Collins & Ware, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 136 | Cologne Production Company | San Antonio, TX 78209 | Oil & Gas Operator | Nov 2014 |
| 137 | Columbia Gas Development Corp. | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 138 | Comstock Oil & Gas, Inc. | Frisco, TX 75034 | Oil & Gas Operator | Dec 2012 |
| 139 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 140 | Continental Trend Resources, Inc | Oklahoma City, OK 73126 | Oil & Gas Operator | Mar 2025 |
| 141 | Cordele Development Corporation | San Antonio, TX 78205 | Oil & Gas Operator | Mar 2025 |
| 142 | Core E & P Corp. | Victoria, TX 77902 | Oil & Gas Operator | Mar 2025 |
| 143 | Corum Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 144 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 145 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 146 | Cougar Oil & Gas Co., Inc. | Houston, TX 77269 | Oil & Gas Operator | Mar 2008 |
| 147 | Crest Petroleum, LLC | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2025 |
| 148 | Crimson Exploration Inc. | Houston, TX 77060 | Oil & Gas Operator | Apr 2006 |
| 149 | Crimson Exploration Oper., Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2019 |
| 150 | Csa Exploration Company, Inc. | Houston, TX 77027 | Oil & Gas Operator | Aug 2003 |
| 151 | CTL Oil & Gas Corporation | Buchanan Dam, TX 78609 | Oil & Gas Operator | Nov 2020 |
| 152 | Cummins & Walker Oil Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2021 |
| 153 | CXL Energy LLC | Canada, 00100 | Oil & Gas Operator | Mar 2025 |
| 154 | Dale Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 155 | Dalport Oil Corporation | Dallas, TX 75202 | Oil & Gas Operator | Apr 1993 |
| 156 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Mar 2025 |
| 157 | Decker Operating Co., L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Mar 2025 |
| 158 | Deguello Operating LLC | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2025 |
| 159 | Delray Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2025 |
| 160 | Delta Exploration Company Inc | Denver, CO 80202 | Oil & Gas Operator | Mar 2025 |
| 161 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 162 | Desana Development Corporation | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 163 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2025 |
| 164 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 165 | Dewbre Petroleum Corporation | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Mar 2025 |
| 166 | Dinero Oil Corporation | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Nov 1999 |
| 167 | Discorbis Oil Company | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2019 |
| 168 | Discovery Energy Corp. CC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Mar 2025 |
| 169 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 170 | Dominion Minerals Corporation | Houston, TX 77014 | Oil & Gas Operator | Nov 2009 |
| 171 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 172 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Dec 2014 |
| 173 | Double Play Oil & Gas, Inc | Portland, TX 78374 | Oil & Gas Operator | Mar 2025 |
| 174 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 175 | Drillers Energy Search, Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 176 | Dune Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Jun 2016 |
| 177 | Durango Resources Corp. | Houston, TX 77043 | Oil & Gas Operator | Mar 2025 |
| 178 | Durst Oil Company | Corpus Chrsti, TX 78477 | Oil & Gas Operator | Sep 2000 |
| 179 | Dynamic Petroleum Res., Inc. | Houston, TX 77068 | Oil & Gas Operator | Jul 1994 |
| 180 | Edge Oil And Gas, LLC | Abilene, TX 79602 | Oil Operator | Mar 2025 |
| 181 | Edge Petroleum Oper. Co., Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 182 | Edisto Resources Corp | Houston, TX 77057 | Oil & Gas Operator | Oct 1999 |
| 183 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Mar 2025 |
| 184 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Jan 2025 |
| 185 | Elliott Oil & Gas Company | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2006 |
| 186 | Ellsworth, H. P. O&G Properties | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Mar 2025 |
| 187 | Emerald Oil & Gas LC | Fort Worth, TX 76109 | Oil & Gas Operator | Mar 2025 |
| 188 | Endeavor Natural Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2015 |
| 189 | Endeavor Natural Gas, LP | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 190 | Enercorp Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 1993 |
| 191 | Energy Resource Management, Inc. | Caldwell, TX 77836 | Oil & Gas Operator | Mar 2008 |
| 192 | Enexco, Inc. | Dallas, TX 75243 | Oil & Gas Operator | Mar 2017 |
| 193 | Engelke, R. H. | San Antonio, TX 78230 | Oil & Gas Operator | Mar 2025 |
| 194 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 195 | Erin Oil Co. | Midland, TX 79707 | Oil & Gas Operator | Mar 2025 |
| 196 | Escoba Royalty Corporation | San Antonio, TX 78217 | Oil & Gas Operator | Nov 2005 |
| 197 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Dec 2024 |
| 198 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 199 | Espada Operating LLC | San Antonio, TX 78209 | Oil Operator | Mar 2025 |
| 200 | Etoco Incorporated | Houston, TX 77002 | Oil & Gas Operator | May 2005 |