| 101 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | May 2025 |
| 102 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 2025 |
| 103 | Chevron Midcontinent, L.P. | Midland, TX 79706 | Oil & Gas Operator | May 2025 |
| 104 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | May 2025 |
| 105 | Chi Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 106 | Chisos Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 107 | Chuza Operating | Midland, TX 79710 | Oil & Gas Operator | Sep 2006 |
| 108 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | May 2025 |
| 109 | Cimarex Energy Co. Of Colorado | Midland, TX 79706 | Oil & Gas Operator | May 2025 |
| 110 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | May 2025 |
| 111 | Clayton Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | May 2004 |
| 112 | Cliffwood Production Co. | Houston, TX 77090 | Oil & Gas Operator | Aug 2013 |
| 113 | CLR Secondary Recovery, LLC | Wichita Falls, TX 76306 | Oil & Gas Operator | May 2025 |
| 114 | CML Exploration, LLC | Austin, TX 78746 | Oil & Gas Operator | May 2025 |
| 115 | Coastal Management Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 116 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 117 | Cochise Energy Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 118 | COG Operating LLC | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 119 | Colgate Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Apr 2024 |
| 120 | Collins & Ware, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 121 | Concho Oil & Gas Corp. | Midland, TX 79701 | Oil & Gas Operator | May 2003 |
| 122 | Concho Oilfield Serv & Oper Co. | Eden, TX 76837 | Oil & Gas Operator | May 2025 |
| 123 | Concho Resources Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2004 |
| 124 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 125 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 126 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | May 2025 |
| 127 | Contango Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 128 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | May 2025 |
| 129 | Coquina Oil Corporation | Houston, TX 77227 | Oil & Gas Operator | Mar 2015 |
| 130 | Corbell, W. D. | Dublin, TX 76446 | Oil & Gas Operator | Dec 2001 |
| 131 | Core E & P Corp. | Victoria, TX 77902 | Oil & Gas Operator | May 2025 |
| 132 | Cory, Kenneth W. LTD. | Bellaire, TX 77401 | Oil & Gas Operator | May 2025 |
| 133 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 134 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 135 | Cottonwood Resources, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Aug 2003 |
| 136 | Cove Petroleum Corporation | Shreveport, LA 71101 | Oil & Gas Operator | Jun 2020 |
| 137 | Cox Exploration, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 1999 |
| 138 | Cox, John L. | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 139 | Craft & Craft Oil Company | Monahans, TX 79756 | Oil Operator | Dec 2024 |
| 140 | Cremson Oil & Gas | Coleman, TX 76834 | Oil & Gas Operator | May 2025 |
| 141 | Cross Timbers Energy, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 142 | Crossing Rocks Energy, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 143 | Crownquest Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 144 | Crystal River Oil & Gas LLC | Snowmass VLG., CO 81615 | Oil & Gas Operator | Jan 2023 |
| 145 | Custer & Wright Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 146 | D & B Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 147 | D & V Oil Co., LP | San Angelo, TX 76909 | Oil & Gas Operator | Jan 2019 |
| 148 | D G D Oil Co. | Imperial, TX 79743 | Oil & Gas Operator | May 2025 |
| 149 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 150 | Dakota Resources, Inc. (I) | Midland, TX 79707 | Oil & Gas Operator | May 2025 |
| 151 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 152 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Feb 2025 |
| 153 | Desert States Energy, Inc. | Hobbs, NM 88240 | Oil & Gas Operator | Aug 1995 |
| 154 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 155 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2025 |
| 156 | Devon Gas Services, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 2015 |
| 157 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 158 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 159 | Diamond G Production | FT Stockton, TX 79735 | Oil & Gas Operator | May 2025 |
| 160 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | May 2025 |
| 161 | Diamondback E&P LLC | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 162 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 163 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 164 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 165 | Dorr, John R. | Pecos, TX 79772 | Oil & Gas Operator | May 2025 |
| 166 | Double Eagle Operating, LLC | Fort Worth, TX 76113 | Oil & Gas Operator | May 2025 |
| 167 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | May 2025 |
| 168 | Draco Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 169 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 170 | Drilmor, Inc. | Midland, TX 79701 | Oil & Gas Operator | Feb 1998 |
| 171 | DSR Oil & Gas, Inc. | Monahans, TX 79756 | Oil & Gas Operator | May 2025 |
| 172 | Dudley Oil Co. | Crane, TX 79731 | Oil & Gas Operator | Jan 2006 |
| 173 | Dugan Production Corp | Farmington, NM 87499 | Oil & Gas Operator | Mar 2025 |
| 174 | Dune Oil And Gas, Inc. | Odessa, TX 79768 | Oil & Gas Operator | Aug 2006 |
| 175 | Dune Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 1997 |
| 176 | Durham, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2016 |
| 177 | E.G.L. Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2025 |
| 178 | Eado Production, Inc. | Kermit, TX 79745 | Oil & Gas Operator | Aug 2012 |
| 179 | Eagle Energy Development Co | La Porte, TX 77571 | Oil & Gas Operator | Dec 2024 |
| 180 | Eagle Energy Resources, LLC | La Porte, TX 77571 | Oil & Gas Operator | May 2025 |
| 181 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | May 2025 |
| 182 | Eagle Rock Operating Company,LLC | Houston, TX 77252 | Oil & Gas Operator | Oct 2015 |
| 183 | Earnest Producing Corporation | Midland, TX 79704 | Oil & Gas Operator | May 2025 |
| 184 | Eason Production Company | Atlanta, TX 75551 | Oil & Gas Operator | May 2007 |
| 185 | Eclipse Oil & Gas, Inc. | Midland, TX 79703 | Oil & Gas Operator | May 2025 |
| 186 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 187 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Mar 2025 |
| 188 | Elevation Resources LLC | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 189 | En Geo, Inc. | Richardson, TX 75081 | Oil & Gas Operator | May 2025 |
| 190 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Apr 2025 |
| 191 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 192 | Energen Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Jan 2021 |
| 193 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Mar 2025 |
| 194 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | Jan 2025 |
| 195 | Energy Transfer Fuel, LP | Houston, TX 77002 | Oil & Gas Operator | Apr 2005 |
| 196 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2025 |
| 197 | Enertex, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 198 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 199 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 200 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |