| 201 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 202 | Coterra Energy Operating Co. | Midland, TX 79706 | Oil & Gas Operator | Sep 2025 |
| 203 | Cottonmouth SWD LLC | Tulsa, OK 74103-3522 | Oil Operator | Aug 2025 |
| 204 | Council Oak Resources LLC | Tulsa, OK 74103-3500 | Oil & Gas Operator | Jul 2025 |
| 205 | Covington Oil Company Inc | Nichols Hills, OK 73116 | Oil & Gas Operator | Sep 2025 |
| 206 | CPRC Inc | Tulsa, OK 74103-5037 | Oil & Gas Operator | Apr 1997 |
| 207 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 208 | CRB Resources Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2025 |
| 209 | Creede Oil & Gas Company | Oklahoma City, OK 73102-7502 | Oil & Gas Operator | Jun 2006 |
| 210 | Cross Don | Cushing, OK 74023-6316 | Oil & Gas Operator | Feb 2022 |
| 211 | Cross Timbers Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2025 |
| 212 | Cross Timbers Production Co | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 2005 |
| 213 | Crown Central Pet Corp | Bellaire, TX 77401 | Oil & Gas Operator | Dec 2016 |
| 214 | Crusader Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2011 |
| 215 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 216 | Crusader Energy Group LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2015 |
| 217 | Crusader Energy II LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 218 | Crusader Energy III LLC | Oklahoma City, OK 73142-1856 | Oil & Gas Operator | Feb 2011 |
| 219 | Crystal Energy Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2019 |
| 220 | Cummings Oil Company | Oklahoma City, OK 73112-6113 | Oil & Gas Operator | Sep 2025 |
| 221 | Curzon Operating Company LTD | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | Aug 2025 |
| 222 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 223 | D & H Oil Inc | Garber, OK 73738-0657 | Oil & Gas Operator | Apr 2021 |
| 224 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Dec 2025 |
| 225 | D & J Oil Company Of Okla Inc | Enid, OK 73706-0129 | Oil & Gas Operator | May 1999 |
| 226 | D & T Swabbing & Well Serv Inc | Hennessey, OK 73742-0124 | Oil & Gas Operator | Aug 2025 |
| 227 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 228 | Dab And Associates Inc | Crescent, OK 73028-0580 | Oil & Gas Operator | Nov 2014 |
| 229 | Dalco Petroleum Inc | | Oil & Gas Operator | Jan 2006 |
| 230 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 231 | Darden Energy Corp | Hennessey, OK 73742 | Oil & Gas Operator | Jul 1999 |
| 232 | Darnell Bobby J | Oklahoma City, OK 73112-8884 | Oil & Gas Operator | Sep 2025 |
| 233 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Sep 2025 |
| 234 | Davco Productions Inc | Springer, OK 73458-8191 | Oil & Gas Operator | Jun 2021 |
| 235 | David E Morgan Inc | Danville, CA 94506-2035 | Oil & Gas Operator | Aug 2025 |
| 236 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Dec 2025 |
| 237 | Davis, William H. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 238 | Dawson Resources Inc | Franktown, CO 80116 | Oil & Gas Operator | Mar 2015 |
| 239 | Dawson-Markwell Exploration Co. | Oklahoma City, OK 73101 | Oil & Gas Operator | Sep 2025 |
| 240 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Aug 2025 |
| 241 | Deck Exploration Inc | Perry, OK 73077-0303 | Oil & Gas Operator | May 2013 |
| 242 | Dedica Energy Corporation | Mattoon, IL 61938 | Oil & Gas Operator | Mar 2008 |
| 243 | Dee-Jay Exploration Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Dec 2025 |
| 244 | Deka Exploration Inc | Oklahoma City, OK 73113-0057 | Oil & Gas Operator | Nov 2019 |
| 245 | Deminex U S Oil Company | | Oil & Gas Operator | Jan 1998 |
| 246 | Denveramerican Petro LLC | | Oil & Gas Operator | May 2006 |
| 247 | Destin Corporation | Enid, OK 73702-2403 | Oil & Gas Operator | Mar 2005 |
| 248 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 249 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 250 | Diamond A Inc. | Tulsa, OK 74137 | Oil & Gas Operator | Jun 2001 |
| 251 | Diamond Energy Operating Company | Tulsa, OK 74137 | Oil & Gas Operator | Mar 2005 |
| 252 | Diamond Energy, Inc. | Sherman, TX 75091 | Oil & Gas Operator | Dec 2025 |
| 253 | Diamond Production Company LLC | Irving, TX 75016-7853 | Oil & Gas Operator | Aug 2025 |
| 254 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 255 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Dec 2025 |
| 256 | Dixie Petroleum Inc | Cashion, OK 73016 | Oil & Gas Operator | May 2001 |
| 257 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 258 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Dec 2025 |
| 259 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | Sep 2025 |
| 260 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 261 | Dorado E & P Partners LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2025 |
| 262 | Dorchester Hugoton LTD | Garland, TX 75042-8212 | Oil & Gas Operator | Mar 2004 |
| 263 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 264 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 265 | Drake Exploration Inc | Tulsa, OK 74105-4250 | Oil & Gas Operator | Sep 2025 |
| 266 | Duncan Jr J Walter | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2016 |
| 267 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 268 | Durango Exploration LLC | Oklahoma City, OK 73120-5309 | Oil & Gas Operator | Sep 2025 |
| 269 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 270 | E & E Enterprises | Enid, OK 73703-1420 | Oil & Gas Operator | Nov 2014 |
| 271 | E Lyle Johnson Inc | Oklahoma City, OK 73142 | Oil & Gas Operator | Aug 2025 |
| 272 | Ea Petroleum Inc | Norman, OK 73072-4147 | Oil & Gas Operator | May 2006 |
| 273 | Eagle Rock Mid-Continent Operating LLC | Tulsa, OK 74103-3703 | Oil & Gas Operator | Aug 2025 |
| 274 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Aug 2025 |
| 275 | Eason Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2012 |
| 276 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2025 |
| 277 | Edinger Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2007 |
| 278 | Edwards & Leach Oil Company | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2005 |
| 279 | Eec Inc | Norman, OK 73069-6344 | Oil & Gas Operator | Sep 2025 |
| 280 | Eight Round Corporation | Seminole, OK 74818-1482 | Oil & Gas Operator | Jul 2012 |
| 281 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 282 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Sep 2025 |
| 283 | Elite Tank Trucks, Inc | | Oil & Gas Operator | Sep 2025 |
| 284 | Elliott Resources Inc | Ada, OK 74820-9227 | Oil & Gas Operator | Jul 2010 |
| 285 | Emc Exploration Company Inc | Oklahoma City, OK 73103-3775 | Oil & Gas Operator | Jul 2007 |
| 286 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Sep 2025 |
| 287 | Endeavor Natural Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2015 |
| 288 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 289 | Entex Petroleum Inc | Oklahoma City, OK 73113 | Oil & Gas Operator | Nov 1997 |
| 290 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 291 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 292 | Eott Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 1995 |
| 293 | Equipment Lott Inc The | Hennessey, OK 73742-0655 | Oil & Gas Operator | Mar 2008 |
| 294 | Esenjay Exploration, Inc | Houston, TX 77042 | Oil & Gas Operator | Aug 2025 |
| 295 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 296 | Essex Energy Inc | Yukon, OK 73099-5126 | Oil & Gas Operator | Apr 2014 |
| 297 | Excelco Energy Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2018 |
| 298 | Exok Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Aug 2025 |
| 299 | Exoko Operating Company Inc | Tulsa, OK 74170-0246 | Oil & Gas Operator | Jan 2006 |
| 300 | Exploration Associates II LLC | Oklahoma City, OK 73102-8815 | Oil & Gas Operator | Jan 2013 |