| 101 | Cimarron Operating Company | Oklahoma City, OK 73112-3967 | Oil & Gas Operator | May 2011 |
| 102 | Citation Oil & Gas Corp | Houston, TX 77269 | Oil & Gas Operator | Apr 2026 |
| 103 | Citizen Energy III LLC | Devner, CO 80202 | Oil & Gas Operator | Jan 2026 |
| 104 | Citizen Energy Ventures LLC | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2026 |
| 105 | Citrus Energy Corporation | Castle Rock, CO 80104 | Oil & Gas Operator | Dec 2025 |
| 106 | Clements Exploration Co | Oklahoma City, OK 73132-5922 | Oil & Gas Operator | Jan 2006 |
| 107 | Clemishire Don | Hominy, OK 74035 | Oil & Gas Operator | Jan 2026 |
| 108 | Clinton Public Works Authority | Clinton, OK 73601 | Oil & Gas Operator | May 2023 |
| 109 | CMS Nomeco Oil & Gas Co. | Jackson, MI 49201 | Oil & Gas Operator | Jan 2015 |
| 110 | Coaleum Corporation | Dallas, TX 75205 | Oil & Gas Operator | Jan 2001 |
| 111 | Coastal Oil & Gas Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 112 | Cobopco Inc | Tulsa, OK 74103-4391 | Oil & Gas Operator | Feb 1997 |
| 113 | Cochran Industrial Corporation | Cushing, OK 74023-1427 | Oil & Gas Operator | Apr 2001 |
| 114 | Cogburn Oil Co Inc | | Oil & Gas Operator | Jan 2026 |
| 115 | Coho Oil & Gas Inc | Coppell, TX 75019-8288 | Oil & Gas Operator | Mar 2015 |
| 116 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 117 | Columbus Energy, LLC | Houston, TX 77046 | Oil & Gas Operator | Apr 2026 |
| 118 | Comanche Exploration Co LLC | Oklahoma City, OK 73116-7334 | Oil & Gas Operator | Feb 2026 |
| 119 | Comanche Resources Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2026 |
| 120 | Complete Energy Services LLC | Gainesville, TX 76240 | Oil Operator | Aug 2022 |
| 121 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 122 | Confederate Spooling Inc | Okemah, OK 74859-2409 | Oil & Gas Operator | Apr 2020 |
| 123 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 124 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 125 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Apr 2026 |
| 126 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Apr 2026 |
| 127 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Apr 2026 |
| 128 | Cooper Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Feb 2026 |
| 129 | Cooper Production Company | New Braunfels, TX 78132 | Oil & Gas Operator | Sep 2021 |
| 130 | Coquina Oil Corporation | Houston, TX 77227 | Oil & Gas Operator | Mar 2015 |
| 131 | Cordillera Energy Partners, LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Mar 2020 |
| 132 | Coterra Energy Operating Co. | Midland, TX 79706 | Oil & Gas Operator | Apr 2026 |
| 133 | Cox, John L. | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 134 | CP Energy, LLC | Edmond, OK 73034 | Oil Operator | Jul 2025 |
| 135 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2026 |
| 136 | Crescendo Resources, L.P. | Amarillo, TX 79188 | Oil & Gas Operator | Jan 2026 |
| 137 | Crest Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2026 |
| 138 | Cross Timbers Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 139 | Cross Timbers Production Co | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 2005 |
| 140 | Crow Oil LLC | Tulsa, OK 74133-2914 | Oil & Gas Operator | Sep 2019 |
| 141 | Curzon Operating Company LTD | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | Jan 2026 |
| 142 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 143 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Apr 2026 |
| 144 | Dalen Resources Oil & Gas Co | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 145 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 146 | Darnell Alma | Bristow, OK 74010 | Oil & Gas Operator | Jun 2000 |
| 147 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Feb 2026 |
| 148 | Davco Productions Inc | Springer, OK 73458-8191 | Oil & Gas Operator | Jun 2021 |
| 149 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Nov 2025 |
| 150 | Decalta International Corp | Denver, CO 80202 | Oil & Gas Operator | Mar 2015 |
| 151 | Deck Oil Company | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2020 |
| 152 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2026 |
| 153 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 154 | Di Energy Inc. | Houston, TX 77067 | Oil & Gas Operator | Jan 2004 |
| 155 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Apr 2026 |
| 156 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 157 | Dominion Exp Midcontinent Inc | Oklahoma City, OK 73134-2616 | Oil & Gas Operator | Oct 2024 |
| 158 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 159 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 160 | Dorchester Minerals Operating LP | Dallas, TX 75219 | Oil & Gas Operator | Jun 2022 |
| 161 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 162 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 163 | DRG Energy Inc. | Norman, OK 73026-3171 | Oil & Gas Operator | Jan 2026 |
| 164 | Duncan Jr J Walter | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2016 |
| 165 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2026 |
| 166 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 167 | E2 Operating LLC | Tulsa, OK 74135 | Oil & Gas Operator | Apr 2026 |
| 168 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2026 |
| 169 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Jan 2026 |
| 170 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2026 |
| 171 | Egolf Operating Company | Oklahoma City, OK 73114-7899 | Oil & Gas Operator | Apr 1998 |
| 172 | Ehvi Exploration LLC | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 173 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 174 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Feb 2026 |
| 175 | Elite Tank Trucks, Inc | | Oil & Gas Operator | Dec 2025 |
| 176 | Enable Gas Transmission LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2022 |
| 177 | Encana Energy Resources Inc | Denver, CO 80202-2828 | Oil & Gas Operator | Feb 2024 |
| 178 | Encino Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2026 |
| 179 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Feb 2026 |
| 180 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | Jan 2026 |
| 181 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 182 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 183 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 184 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 185 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 186 | EP Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 187 | Esco Exploration, Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 188 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 189 | Evergreen Operating Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 190 | Evolution Energy LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2026 |
| 191 | Excalibur Resources LLC | Houston, TX 77002-5220 | Oil & Gas Operator | Feb 2026 |
| 192 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Jan 2026 |
| 193 | Exok Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Jan 2026 |
| 194 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Apr 2026 |
| 195 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Jan 2026 |
| 196 | Fairway Resources Operating III LLC | Houston, TX 77002-2728 | Oil & Gas Operator | Jan 2026 |
| 197 | Fairway Resources Operating, LLC | Southlake, TX 76092 | Oil & Gas Operator | Aug 2022 |
| 198 | Felix Energy LLC | Denver, CO 80202-1467 | Oil & Gas Operator | Jan 2026 |
| 199 | Femco SWD Inc | Enid, OK 73702-3907 | Oil Operator | Mar 2014 |
| 200 | Flow Production Company | Midland, TX 79708 | Oil & Gas Operator | Mar 2005 |