| 101 | C.D. Operating Company, Inc. | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2015 |
| 102 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Jun 2025 |
| 103 | Cactus Energy Company LLC | Hennessey, OK 73742 | Oil & Gas Operator | Jul 2025 |
| 104 | Cain Richard | Comanche, OK 73529-1248 | Oil & Gas Operator | May 2020 |
| 105 | Canaan Exploration Inc | Oklahoma City, OK 73123 | Oil & Gas Operator | Jan 1998 |
| 106 | Canok International Inc | Okmulgee, OK 74447 | Oil & Gas Operator | Jul 2025 |
| 107 | Canvas Energy LLC | Oklahoma City, OK 73142-1839 | Oil & Gas Operator | Jul 2025 |
| 108 | Carl E Gungoll Exploration LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Jul 2025 |
| 109 | Carl Humphries Inc | Piedmont, OK 73078-0514 | Oil & Gas Operator | Jul 2025 |
| 110 | Case Sales Company Inc | Tonkawa, OK 74653-0040 | Oil & Gas Operator | Jul 2025 |
| 111 | Ceja Corporation | Tulsa, OK 74172 | Oil & Gas Operator | Jul 2025 |
| 112 | Centaur Resources Inc | Oklahoma City, OK 73142-6804 | Oil & Gas Operator | Jul 2025 |
| 113 | Centrex Operating Company | Tulsa, OK 74105 | Oil & Gas Operator | Jun 2025 |
| 114 | Cep Mid-Continent LLC | Skiatook, OK 74070 | Oil & Gas Operator | Jun 2025 |
| 115 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Aug 2025 |
| 116 | Charter Oak Production Co LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Oct 2025 |
| 117 | Cherokee Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 118 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Oct 2025 |
| 119 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 120 | Chizum Oil LLC | Wichita, KS 67211 | Oil & Gas Operator | Jun 2025 |
| 121 | Choate Kenny Dba Rebound Oil Co | Helena, OK 73741-0543 | Gas Operator | Jul 2025 |
| 122 | Christa Oil Co | Cumberland, OH 43732 | Oil & Gas Operator | Nov 1999 |
| 123 | Cimarron Oil & Gas Inc | Perry, OK 73077-1318 | Oil & Gas Operator | Sep 2000 |
| 124 | Cisco Operating LLC | Plano, TX 75024 | Oil & Gas Operator | Jun 2025 |
| 125 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Oct 2025 |
| 126 | Claremont Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Feb 2017 |
| 127 | Clifton & Associates Inc | Tulsa, OK 74133 | Oil & Gas Operator | May 2020 |
| 128 | Co-St Oil Operating Co Inc | Enid, OK 73706 | Oil & Gas Operator | Apr 1997 |
| 129 | Columbia Production Company | Edmond, OK 73083 | Oil & Gas Operator | May 2020 |
| 130 | Combined Resources Corporation | Edmond, OK 73083 | Oil & Gas Operator | Oct 2025 |
| 131 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 132 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 133 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 134 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 135 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 136 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 137 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Oct 2025 |
| 138 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 139 | Cooper Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Jul 2025 |
| 140 | Cornelius Petroleum Inc | | Oil & Gas Operator | Jul 2025 |
| 141 | Coronado Petroleum Corporation | Oklahoma City, OK 73102-4803 | Oil & Gas Operator | Jul 2025 |
| 142 | Covington Oil Company Inc | Nichols Hills, OK 73116 | Oil & Gas Operator | Jun 2025 |
| 143 | Cow Creek Resources Inc | Ponca City, OK 74601-7815 | Oil & Gas Operator | Jul 2025 |
| 144 | Crain & Deisenroth | Tulsa, OK 74103-4433 | Oil & Gas Operator | Mar 2015 |
| 145 | Crain & Deisenroth LLC | Tulsa, OK 74104-6511 | Oil & Gas Operator | Apr 2014 |
| 146 | Crain Minerals LLC | Oklahoma City, OK 73120-1004 | Oil & Gas Operator | Aug 2014 |
| 147 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 148 | Cromer Carroll Oil & Gas LLC | Kalispell, MT 59901 | Oil & Gas Operator | Jun 2025 |
| 149 | Cross Timbers Operating Co | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2025 |
| 150 | Cross Timbers Production Co | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 2005 |
| 151 | Cross, Don E | | Oil & Gas Operator | Jan 2013 |
| 152 | Crow Creek Operating Co III LLC | Tulsa, OK 74137-8432 | Oil & Gas Operator | Apr 2015 |
| 153 | Crown Energy Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Jun 2025 |
| 154 | Crusader Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2011 |
| 155 | Crystal Energy Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2019 |
| 156 | Culp & Copple Oil Company | Cushing, OK 74023 | Oil & Gas Operator | Jun 2025 |
| 157 | Curran Oil Co | Great Falls, MT 59401 | Gas Operator | May 2001 |
| 158 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 159 | D & G Oil & Gas Company Inc | Enid, OK 73702-2027 | Oil & Gas Operator | Nov 2021 |
| 160 | D & H Oil Inc | Garber, OK 73738-0657 | Oil & Gas Operator | Apr 2021 |
| 161 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Oct 2025 |
| 162 | D & M Production Co Inc | Drumright, OK 74030 | Oil & Gas Operator | Jun 2025 |
| 163 | D B D Oil & Gas Company | Houston, TX 77001 | Oil & Gas Operator | Mar 2015 |
| 164 | Dakota Exploration LLC | Tulsa, OK 74136 | Oil & Gas Operator | Jul 2025 |
| 165 | Darling Dan Oil | | Oil & Gas Operator | Sep 2018 |
| 166 | Darling Oil Corporation | Lamont, OK 74643 | Oil & Gas Operator | Jul 2025 |
| 167 | Darnell Bobby J | Oklahoma City, OK 73112-8884 | Oil & Gas Operator | Jul 2025 |
| 168 | Dauco Petroleum Corporation | Rowlett, TX 75089-3066 | Oil & Gas Operator | Jan 2021 |
| 169 | Davidson Energy Inc | Perry, OK 73077 | Oil & Gas Operator | Jul 2025 |
| 170 | Davidson Gene | Perry, OK 73077-0144 | Oil & Gas Operator | Aug 2014 |
| 171 | Davies & Company | Tulsa, OK 74114 | Oil & Gas Operator | Nov 2000 |
| 172 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Oct 2025 |
| 173 | Davis, William H. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 174 | Dawson-Markwell Exploration Co. | Oklahoma City, OK 73101 | Oil & Gas Operator | Jun 2025 |
| 175 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 176 | Deck Exploration Inc | Perry, OK 73077-0303 | Oil & Gas Operator | May 2013 |
| 177 | Deck Oil Company | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2020 |
| 178 | Deka Exploration Inc | Oklahoma City, OK 73113-0057 | Oil & Gas Operator | Nov 2019 |
| 179 | Delong Ralph J | Sapulpa, OK 74066 | Oil & Gas Operator | Nov 2005 |
| 180 | Deminex U.S. Oil Company | | Oil & Gas Operator | Jan 1998 |
| 181 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 182 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 183 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 184 | Diamond Production Company LLC | Irving, TX 75016-7853 | Oil & Gas Operator | Jun 2025 |
| 185 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 186 | Domac Oil Company Inc | Perkins, OK 74059-0642 | Oil & Gas Operator | Feb 2006 |
| 187 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 188 | Donray Petroleum LLC | Choctaw, OK 73020 | Oil & Gas Operator | Jun 2025 |
| 189 | Dorado E & P Partners LLC | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2025 |
| 190 | Dorado Energy LLC | Edmond, OK 73012 | Oil & Gas Operator | Jan 2021 |
| 191 | Double C Oil & Gas LLC | Jenks, OK 74037-6946 | Oil Operator | May 2025 |
| 192 | DRG Energy Inc | Norman, OK 73026-3171 | Oil & Gas Operator | Jun 2025 |
| 193 | Driver Energy Of Texas | Dallas, TX 75379-5951 | Oil & Gas Operator | Apr 2011 |
| 194 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 195 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 196 | Eagle Creek Resources, LLC | Sewickley, PA 15143 | Oil & Gas Operator | Dec 2024 |
| 197 | Eagle Road Oil LLC | Tulsa, OK 74103-3312 | Oil & Gas Operator | Jul 2025 |
| 198 | Eagle Rock Mid-Continent Operating LLC | Tulsa, OK 74103-3703 | Oil & Gas Operator | Jun 2025 |
| 199 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Jun 2025 |
| 200 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |