| 1301 | Dunbar & Son Oil | | Oil & Gas Operator | Oct 1988 |
| 1302 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 1303 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 1304 | Dunham'S Oil, LLC | Eureka, KS 67045 | Oil Operator | May 2025 |
| 1305 | Dunne Equities I | | Oil & Gas Operator | Dec 1995 |
| 1306 | Dunne Equities Operating, Inc. | Houston, TX 77057 | Oil & Gas Operator | Aug 2022 |
| 1307 | Dunne Equities, Inc. | Wichita, KS 67226 | Oil & Gas Operator | Apr 2014 |
| 1308 | Dunne Investments Operating, Inc. | Wichita, KS 67226 | Oil Operator | Mar 2002 |
| 1309 | Dunne Oil Co. | Wichita, KS 67202 | Oil Operator | Apr 1999 |
| 1310 | Dunne-Gardner Pe | | Oil & Gas Operator | Nov 1992 |
| 1311 | Dunne-Gardner Petroleum, Inc. | Wichita, KS 67202 | Gas Operator | Jun 2022 |
| 1312 | Dunsmoor, David E. | Grand Junction, CO 81504 | Oil Operator | Jul 1998 |
| 1313 | Durbin, Ronald R. | Moline, KS 67353 | Oil Operator | Dec 1988 |
| 1314 | Dustin Enterprise | Olathe, KS 66062 | Oil Operator | Feb 1998 |
| 1315 | Dutton Bill J Oi | | Oil & Gas Operator | Oct 1992 |
| 1316 | Dwarf Oil Company | | Oil & Gas Operator | Mar 2025 |
| 1317 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 1318 | Dyer, Charles Wilbur | Longton, KS 67352 | Oil Operator | Nov 2024 |
| 1319 | E & B Natural Resources Management Corporation | Hays, KS 67601 | Oil & Gas Operator | Oct 2025 |
| 1320 | E & E Oil | | Oil Operator | Dec 2019 |
| 1321 | E K Energy LLC | Colony, KS 66015 | Oil Operator | Jun 2025 |
| 1322 | E O R Petroleum | | Oil Operator | Oct 1987 |
| 1323 | E R Operating Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2025 |
| 1324 | E S P Developmne | | Oil Operator | Oct 1993 |
| 1325 | E&E Oil LLC | Canton, KS 67428 | Oil Operator | Jun 2025 |
| 1326 | E. L. Daniels Drilling Contractor | | Oil Operator | Feb 2014 |
| 1327 | E2 Operating LLC | Tulsa, OK 74135 | Oil & Gas Operator | Dec 2025 |
| 1328 | Eads Operating C | | Oil Operator | Jun 1990 |
| 1329 | Eagle Creek Corporation | Andover, KS 67002 | Oil & Gas Operator | Jun 2025 |
| 1330 | Eagle Creek Resources, LLC | Sewickley, PA 15143 | Oil & Gas Operator | Dec 2024 |
| 1331 | Eagle Energy | Midland, TX 79710 | Oil & Gas Operator | Aug 1994 |
| 1332 | Eagle Energy Resources, LLC | La Porte, TX 77571 | Oil & Gas Operator | Dec 2025 |
| 1333 | Eagle Energy, Inc. | Moreland, KS 67650 | Oil & Gas Operator | Dec 2021 |
| 1334 | Eagle Exploratio | | Oil & Gas Operator | Oct 1991 |
| 1335 | Eagle Exploration Co., Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Dec 2019 |
| 1336 | Eagle Oil Compan | | Oil Operator | Jul 1990 |
| 1337 | Eagle Oil, LLC | Moline, KS 67353 | Oil Operator | Oct 2016 |
| 1338 | Eagle Petroleum | | Oil & Gas Operator | Nov 1995 |
| 1339 | Eagle Petroleum, Inc. | Ellinwood, KS 67526 | Oil Operator | Jun 2025 |
| 1340 | Eagle Resources | | Oil & Gas Operator | Mar 1987 |
| 1341 | Eagle River Ener | | Oil Operator | Dec 1996 |
| 1342 | Eagle River Energy Corporation | Broken Arrow, OK 74011 | Oil & Gas Operator | Aug 2025 |
| 1343 | Earco Oil Operations, Inc. | McPherson, KS 67460 | Oil Operator | Mar 1999 |
| 1344 | Earth Scientists | | Oil Operator | Jan 1986 |
| 1345 | Eason Drilling & Services Co. | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2005 |
| 1346 | Eastern Kansas Operating, LLC | Sun Lakes, AZ 85248 | Oil & Gas Operator | Apr 2018 |
| 1347 | Eastern Petroleu | | Oil & Gas Operator | Oct 1993 |
| 1348 | Easy Street Oil, Inc. | Iola, KS 66749 | Oil Operator | Sep 1999 |
| 1349 | Eby Oil Co. | | Oil Operator | Sep 2017 |
| 1350 | Ecco | | Oil Operator | Jun 2025 |
| 1351 | Echelon Land & Exploration Co. | Havana, FL 32333 | Oil Operator | Apr 1997 |
| 1352 | Eck Petroleum LLC | Kingman, KS 67068 | Oil Operator | Nov 2019 |
| 1353 | Edinger Incorpor | | Oil Operator | Oct 1986 |
| 1354 | Edison Operating Company LLC | Wichita, KS 67226 | Oil & Gas Operator | Jun 2025 |
| 1355 | Edmiston Oil Com | | Oil & Gas Operator | May 1994 |
| 1356 | Edmiston Oil Company, Inc. | Wichita, KS 67202 | Oil & Gas Operator | Jun 2025 |
| 1357 | Edwards Lease,The | | Oil Operator | Oct 2016 |
| 1358 | Edwards Oil Inco | | Oil Operator | Oct 1984 |
| 1359 | Edwards Oil Properties | | Oil Operator | Dec 2009 |
| 1360 | Ego Operating LLC | Boca Raton, FL 33431 | Oil Operator | Dec 2019 |
| 1361 | Einsel Gas Marketing | | Gas Operator | Feb 2019 |
| 1362 | Eitel Energy, LLC | Farlington, KS 66734 | Oil Operator | May 2025 |
| 1363 | El Chjon Gas Com | | Gas Operator | May 1988 |
| 1364 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 1365 | El-Kan Exploration | Garfield, KS 67529 | Oil Operator | Jul 1997 |
| 1366 | Elb Enterprise LLC | | Oil Operator | Jun 2025 |
| 1367 | Elendil Resources LLC | Pampa, TX 79066 | Oil & Gas Operator | Dec 2025 |
| 1368 | Elevate Energy LTD | Aurora, CO 80016 | Oil & Gas Operator | Jun 2025 |
| 1369 | Eleven Eleven Investments, LLC | Hays, KS 67601 | Oil Operator | May 2025 |
| 1370 | Elk City Oil Field Service | Elk City, KS 67344 | Oil Operator | Oct 1996 |
| 1371 | Elk Energy Holdings LLC | Wichita, KS 67226 | Oil & Gas Operator | Jun 2025 |
| 1372 | Elk Oil Company | Overland Park, KS 66212 | Oil & Gas Operator | Sep 2007 |
| 1373 | Elk Oil Enterprises, LLC | Wetmore, KS 66550 | Oil Operator | Dec 2009 |
| 1374 | Elkhound Resources Inc | Wellsville, KS 66092 | Oil Operator | Aug 1998 |
| 1375 | Ellinwood Oil Reclaiming Inc | | Oil Operator | Oct 2009 |
| 1376 | Ellinwood Tank Service, Inc. | Chase, KS 67524 | Oil Operator | Jul 2022 |
| 1377 | Elliott Phillip | | Oil Operator | Feb 1992 |
| 1378 | Ellsworth Systems, Inc. | Wichita, KS 67202 | Oil & Gas Operator | May 2005 |
| 1379 | Elm Creek Oil, LLC | | Oil Operator | Jun 2025 |
| 1380 | Elm III Operating Company LLC | Edmond, OK 73013 | Oil & Gas Operator | Jun 2025 |
| 1381 | Elmer L. Karst Oil, A General Partnership | Russell, KS 67665 | Oil Operator | Jun 2025 |
| 1382 | Elmore Farm | | Oil Operator | Sep 2009 |
| 1383 | Elmore, John A. And Patricia R. | Sedan, KS 67361 | Oil Operator | Jun 2025 |
| 1384 | Elwell, Mike | Lawrence, KS 66044 | Oil Operator | Dec 2009 |
| 1385 | Elysium Energy, L.L.C | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 1386 | Emc Properties, LLC | Clinton, MO 64735 | Oil Operator | Dec 2019 |
| 1387 | Emerson, Jim | Plano, TX 75074 | Oil & Gas Operator | Jan 1995 |
| 1388 | Empire Energy E & P, LLC | Mayville, NY 14757 | Oil & Gas Operator | Mar 2019 |
| 1389 | Empire Explorati | | Oil Operator | Dec 1996 |
| 1390 | Empire Exploration Inc | Wichita, KS 67202 | Oil & Gas Operator | Jul 1997 |
| 1391 | En/Drill America, Inc. | Crystal, MN 55428 | Oil & Gas Operator | Apr 2009 |
| 1392 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 1393 | Encore Operating Company | Denver, CO 80227 | Oil & Gas Operator | Dec 2019 |
| 1394 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Sep 2025 |
| 1395 | Encorp, Inc. | Wichita, KS 67206 | Oil Operator | May 2007 |
| 1396 | End Of The Trails Re | | Oil Operator | Jun 2025 |
| 1397 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 1398 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 1399 | Energy Explorati | | Oil & Gas Operator | Oct 1993 |
| 1400 | Energy Exploration & Production, Inc. | Wichita, KS 67201 | Oil Operator | Jan 2004 |