| 1201 | Dolphin Energy LLC | Lake Worth, FL 33467 | Oil & Gas Operator | Dec 2025 |
| 1202 | Domar Oil & Gas | | Gas Operator | May 1995 |
| 1203 | Domar Oil & Gas Inc | Liberal, KS 67905 | Oil & Gas Operator | Oct 2000 |
| 1204 | Dominion Oklahoma Texas Expl & Prod Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Aug 2013 |
| 1205 | Don Erbert Oil Company | | Oil Operator | Oct 2013 |
| 1206 | Don Karst Well Service, Inc. | Russell, KS 67665 | Oil Operator | Sep 2025 |
| 1207 | Don Sims Oil | | Oil Operator | Dec 2025 |
| 1208 | Donald C. Slawson | | Oil Operator | Jun 1985 |
| 1209 | Donke Oil & Gas, LLC | Tulsa, OK 74137 | Oil & Gas Operator | Mar 2018 |
| 1210 | Donna Lee Oil Co | Independence, KS 67301 | Oil & Gas Operator | Apr 2014 |
| 1211 | Doodlebug Oil Co | | Oil Operator | Jun 2006 |
| 1212 | Doonan & Sons In | | Oil Operator | Apr 1995 |
| 1213 | Doonan And Sons, Inc. | Great Bend, KS 67530 | Oil Operator | Apr 2021 |
| 1214 | Dorado E & P Partners LLC | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2026 |
| 1215 | Dorado Gas Resources LLC | Centennial, CO 80112 | Oil & Gas Operator | Jul 2009 |
| 1216 | Doralex Energy I | | Oil & Gas Operator | Feb 1995 |
| 1217 | Doralex Energy, Inc. | San Angelo, TX 76904 | Oil Operator | Feb 2000 |
| 1218 | Dorchester Exploration, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 2001 |
| 1219 | Dorchester Hugot | | Gas Operator | Sep 1993 |
| 1220 | Dorchester Minerals Operating LP | Dallas, TX 75219 | Oil & Gas Operator | Jun 2022 |
| 1221 | Dotson, Floyd | | Oil Operator | Dec 1980 |
| 1222 | Doty, Tim | Sedan, KS 67361 | Oil Operator | Dec 2009 |
| 1223 | Double "K" Oil, Inc. | Ellis, KS 67637 | Oil Operator | Dec 2019 |
| 1224 | Double 'B' Oil Co | | Oil Operator | Nov 2009 |
| 1225 | Double 'B' Oil I | | Oil Operator | Feb 1992 |
| 1226 | Double 'E' Oil-B | | Oil Operator | Mar 1989 |
| 1227 | Double D Oil Co | Winfield, KS 67156 | Oil Operator | Dec 2025 |
| 1228 | Double D'S LLC | Hays, KS 67601 | Oil Operator | Nov 2025 |
| 1229 | Double Eagle Exp | | Oil Operator | Jul 1992 |
| 1230 | Double Eagle Exploration Inc | Windthorst, TX 76389 | Oil Operator | Dec 2025 |
| 1231 | Double Eagle Resources, LLC | FT Smith, AR 72901 | Oil & Gas Operator | Sep 2009 |
| 1232 | Double F Oil Co. | | Oil Operator | Jun 2009 |
| 1233 | Double G Petro LLC | | Oil Operator | Dec 2025 |
| 1234 | Double L Drilling | Yates Center, KS 66783 | Oil Operator | Jun 2000 |
| 1235 | Double L Oil Producers | | Oil Operator | Dec 2019 |
| 1236 | Double R Oil Co. | Charlotte, TX 78011 | Oil & Gas Operator | May 2010 |
| 1237 | Double Ten Petro | | Oil Operator | Jul 1994 |
| 1238 | Doudna, Mark A. | Osawatomie, KS 66064 | Oil Operator | Nov 2009 |
| 1239 | Doug'S Pumping Service | | Oil Operator | Nov 2025 |
| 1240 | Dover Atwood Corp. | Massillon, OH 44646 | Oil & Gas Operator | Dec 2025 |
| 1241 | Downing-Nelson Oil Co Inc | Hays, KS 67601 | Oil & Gas Operator | Dec 2025 |
| 1242 | DR Well Operator | | Oil Operator | Jan 1990 |
| 1243 | Drake Exploration LLC | Arkansas City, KS 67005 | Oil & Gas Operator | Feb 2026 |
| 1244 | Dreiling Exploration LLC | Victoria, KS 67671 | Oil Operator | Mar 2018 |
| 1245 | Dreiling Limited | | Oil Operator | Jun 1984 |
| 1246 | Dreiling Oil Inc | Hays, KS 67601 | Oil Operator | Jun 2018 |
| 1247 | Dreiling Resourc | | Oil Operator | Oct 1996 |
| 1248 | Dreiling Resources Inc. | Victoria, KS 67671 | Oil Operator | Sep 1997 |
| 1249 | Dreyer Oil | | Oil Operator | Dec 2019 |
| 1250 | Dreyer Oil - Lel | | Oil Operator | Nov 1993 |
| 1251 | Driftwood Oil Co. | Russell, KS 67665 | Oil Operator | Jan 1988 |
| 1252 | Drilex Oil & Gas | | Oil Operator | Apr 1987 |
| 1253 | Driller'S & Prod | | Oil & Gas Operator | Oct 1994 |
| 1254 | Drillers & Producers, Inc. | Newton, KS 67114 | Oil Operator | Dec 2019 |
| 1255 | Driscoll Jerry J | | Oil Operator | Apr 1994 |
| 1256 | Driscoll Lease O | | Oil Operator | Jul 1988 |
| 1257 | Driscoll Lease Operations, Inc. | Russell, KS 67665 | Oil Operator | Dec 1998 |
| 1258 | Driscoll, Jerry J Oil Investment Inc | Russell, KS 67665 | Oil Operator | Dec 2025 |
| 1259 | DRL Operating In | | Oil Operator | Sep 1986 |
| 1260 | Drop Tine Exploration, LLC | Medicine Lodge, KS 67104 | Oil & Gas Operator | Dec 2019 |
| 1261 | Du Pont Oil Comp | | Oil Operator | May 1984 |
| 1262 | Duane Exploration Limited | Andover, KS 67002 | Oil Operator | Jul 1996 |
| 1263 | Dubois, Allen | Whitewater, KS 67154 | Oil Operator | May 2000 |
| 1264 | Dudrey Carl | | Oil & Gas Operator | Feb 1993 |
| 1265 | Duke Drilling Co | Wichita, KS 67202 | Oil & Gas Operator | Feb 2006 |
| 1266 | Duke Oil & Gas Company, LLC | Wellsville, KS 66092 | Oil Operator | Dec 2025 |
| 1267 | Duke Oil LLC | Garnett, KS 66032 | Oil Operator | Dec 2025 |
| 1268 | Dunbar & Son Oil | | Oil & Gas Operator | Oct 1988 |
| 1269 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 1270 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2026 |
| 1271 | Dunham'S Oil, LLC | Eureka, KS 67045 | Oil Operator | Dec 2025 |
| 1272 | Dunne Equities I | | Oil & Gas Operator | Dec 1995 |
| 1273 | Dunne Equities Operating, Inc. | Houston, TX 77057 | Oil & Gas Operator | Aug 2022 |
| 1274 | Dunne Equities, Inc. | Wichita, KS 67226 | Oil & Gas Operator | Apr 2014 |
| 1275 | Dunne Investments Operating, Inc. | Wichita, KS 67226 | Oil Operator | Mar 2002 |
| 1276 | Dunne Oil Co. | Wichita, KS 67202 | Oil Operator | Apr 1999 |
| 1277 | Dunne-Gardner Pe | | Oil & Gas Operator | Nov 1992 |
| 1278 | Dunne-Gardner Petroleum, Inc. | Wichita, KS 67202 | Gas Operator | Jun 2022 |
| 1279 | Dunsmoor, David E. | Grand Junction, CO 81504 | Oil Operator | Jul 1998 |
| 1280 | Durbin, Ronald R. | Moline, KS 67353 | Oil Operator | Dec 1988 |
| 1281 | Dustin Enterprise | Olathe, KS 66062 | Oil Operator | Feb 1998 |
| 1282 | Dutton Bill J Oi | | Oil & Gas Operator | Oct 1992 |
| 1283 | Dwarf Oil Company | | Oil & Gas Operator | Mar 2025 |
| 1284 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 1285 | Dyer, Charles Wilbur | Longton, KS 67352 | Oil Operator | Jul 2025 |
| 1286 | E & B Natural Resources Management Corporation | Hays, KS 67601 | Oil & Gas Operator | Dec 2025 |
| 1287 | E & E Oil | | Oil Operator | Dec 2019 |
| 1288 | E K Energy LLC | Colony, KS 66015 | Oil Operator | Dec 2025 |
| 1289 | E O R Petroleum | | Oil Operator | Oct 1987 |
| 1290 | E R Operating Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2025 |
| 1291 | E S P Developmne | | Oil Operator | Oct 1993 |
| 1292 | E&E Oil LLC | Canton, KS 67428 | Oil Operator | Dec 2025 |
| 1293 | E. L. Daniels Drilling Contractor | | Oil Operator | Feb 2014 |
| 1294 | E2 Operating LLC | Tulsa, OK 74135 | Oil & Gas Operator | Apr 2026 |
| 1295 | Eads Operating C | | Oil Operator | Jun 1990 |
| 1296 | Eagle Creek Corporation | Andover, KS 67002 | Oil & Gas Operator | Dec 2025 |
| 1297 | Eagle Creek Resources, LLC | Sewickley, PA 15143 | Oil & Gas Operator | Dec 2024 |
| 1298 | Eagle Energy | Midland, TX 79710 | Oil & Gas Operator | Aug 1994 |
| 1299 | Eagle Energy Resources, LLC | La Porte, TX 77571 | Oil & Gas Operator | Apr 2026 |
| 1300 | Eagle Energy, Inc. | Moreland, KS 67650 | Oil & Gas Operator | Dec 2021 |