| 301 | Danmark Energy Services, Inc. | White Oak, TX 75693 | Oil & Gas Operator | Apr 2021 |
| 302 | Dannic Energy Corp | Indiana, PA 15701-1532 | Oil & Gas Operator | Dec 2025 |
| 303 | Danny Engel Operating LLC | Ada, OK 74820-1388 | Oil Operator | May 2026 |
| 304 | Danny Glass | | Oil Operator | Jan 1987 |
| 305 | Danny Long & Sons Inc | Magnolia, OH 44643 | Oil & Gas Operator | Dec 2025 |
| 306 | Danos Oil & Gas LLC | | Oil & Gas Operator | Oct 2024 |
| 307 | Dant Operating Company Inc. | | Oil & Gas Operator | Jan 1989 |
| 308 | Dantex Oil & Gas, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 309 | Dao Oil And Gas | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Sep 2026 |
| 310 | Dapsco, Inc. | | Oil & Gas Operator | Dec 1976 |
| 311 | Dar-Lon Operating Company | Lamont, OK 74643 | Oil & Gas Operator | Oct 2000 |
| 312 | Dara Explorations, LLC | Albany, TX 76430 | Oil Operator | Sep 2026 |
| 313 | Dara Operating Company, LLC | Electra, TX 76360 | Oil & Gas Operator | May 2026 |
| 314 | Darco Operators | Big Lake, TX 76932 | Oil & Gas Operator | Sep 2026 |
| 315 | Darco Petroleum Inc | Bartlesville, OK 74005 | Oil & Gas Operator | Dec 2020 |
| 316 | Dardan Expl Inc-H Edison Ellis | | Oil & Gas Operator | Apr 1990 |
| 317 | Darden Energy Corp | Hennessey, OK 73742 | Oil & Gas Operator | Jul 1999 |
| 318 | Dark Canyon Resources LLC | Refugio, TX 78377 | Oil Operator | Sep 2026 |
| 319 | Dark Horse | | Oil Operator | Mar 2026 |
| 320 | Dark Horse Operating Co., L.L.C. | Denton, TX 76202 | Oil & Gas Operator | Oct 2022 |
| 321 | Dark Horse Producing Of TX, L.P. | Alice, TX 78333 | Oil & Gas Operator | Sep 2026 |
| 322 | Darkens Oil & Gas Inc. | MC Camey, TX 79752 | Oil & Gas Operator | Sep 2026 |
| 323 | Darley Enterprises, Inc. | Brownwood, TX 76801 | Oil & Gas Operator | Jan 2012 |
| 324 | Darling Dan Oil | | Oil & Gas Operator | Sep 2018 |
| 325 | Darling Oil Corporation | Lamont, OK 74643 | Oil & Gas Operator | May 2026 |
| 326 | Darnall, Eric W | Sedan, KS 67361 | Oil Operator | Apr 2026 |
| 327 | Darnall, Walter E. | Chautauqua, KS 67334 | Oil Operator | Dec 2009 |
| 328 | Darnell Alma | Bristow, OK 74010 | Oil & Gas Operator | Jun 2000 |
| 329 | Darnell Bobby J | Oklahoma City, OK 73112-8884 | Oil & Gas Operator | Jun 2026 |
| 330 | Darr-Hey Oil, LLC | Iowa Park, TX 76367 | Oil & Gas Operator | Sep 2026 |
| 331 | Darrah John J Jr | | Oil & Gas Operator | Oct 1994 |
| 332 | Darrah John Jay Jr | Wichita, KS 67201 | Oil & Gas Operator | Jul 2026 |
| 333 | Darrah Oil Company, LLC | Wichita, KS 67201 | Oil & Gas Operator | Sep 2026 |
| 334 | Darrell'S Drilling Inc | Konawa, OK 74849 | Oil Operator | May 2026 |
| 335 | Darriel C Ray | | Oil Operator | Jun 2020 |
| 336 | Darsey Operating Corporation | | Oil & Gas Operator | Sep 1990 |
| 337 | Darst Creek Oil Company | Lockhart, TX 78644 | Oil & Gas Operator | Mar 2021 |
| 338 | Dart Cherokee Basin Operating Co., LLC | Mason, MI 48854 | Oil & Gas Operator | Apr 2026 |
| 339 | Dart Oil & Gas Corporation | Mason, MI 48854 | Oil & Gas Operator | Jun 2018 |
| 340 | Dart Oil & Gas Ohio LLC | Mason, MI 48854 | Oil Operator | Dec 2018 |
| 341 | Dart Oil Company | Parker, CO 80134 | Oil & Gas Operator | Dec 2025 |
| 342 | Dart Oil Properties | Enid, OK 73703 | Oil & Gas Operator | Oct 1992 |
| 343 | Dartex Energy Corporation | Austin, TX 78731 | Oil & Gas Operator | Sep 2026 |
| 344 | Dartex Energy Inc | Graham, TX 76450 | Oil & Gas Operator | Sep 2026 |
| 345 | Darwin Allen Dba Wil-Mar Operations | Duncan, OK 73534-1566 | Oil & Gas Operator | Oct 2016 |
| 346 | Das Oil Co. L.L.C. | Post, TX 79356 | Oil Operator | Sep 2026 |
| 347 | Dasbek Energy, L.L.C. | Sugar Land, TX 77479 | Oil & Gas Operator | Sep 2026 |
| 348 | Dash Operating LLC | Oklahoma City, OK 73118-5031 | Oil & Gas Operator | May 2026 |
| 349 | Dash Production Company, Inc. | Corpus Christ, TX 78411 | Oil & Gas Operator | Sep 2026 |
| 350 | Data Energy Inc | Evergreen, CO 80439 | Oil & Gas Operator | Jul 2018 |
| 351 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Jul 2026 |
| 352 | Daube Exploration Company | Ardmore, OK 73402 | Oil & Gas Operator | Nov 2020 |
| 353 | Daubert Operating, L.L.C. | San Antonio, TX 78209 | Oil Operator | Sep 2026 |
| 354 | Dauco Petroleum Corporation | Rowlett, TX 75089-3066 | Oil & Gas Operator | Jan 2021 |
| 355 | Daughenbaugh, James And Meshelle | Gerry, NY 14740 | Gas Operator | Dec 2025 |
| 356 | Davco Drilling Co. | | Gas Operator | Dec 2001 |
| 357 | Davco Oil LLC | Fort Worth, TX 76108 | Oil & Gas Operator | Sep 2026 |
| 358 | Davco Productions Inc | Springer, OK 73458-8191 | Oil & Gas Operator | Jun 2021 |
| 359 | Davcro Inc. | Lubbock, TX 79401 | Oil & Gas Operator | Dec 2003 |
| 360 | Dave Easom Production Co. Inc. | | Oil & Gas Operator | May 2000 |
| 361 | Dave M Thomas Jr | Farmington, NM 87499 | Oil & Gas Operator | Aug 1995 |
| 362 | Dave Shrader Oil FLD SVC Inc | Endeavor, PA 16322-0189 | Oil & Gas Operator | Dec 2025 |
| 363 | Dave'S Production | | Oil Operator | Dec 2024 |
| 364 | Davenport Oil Company | Luling, TX 78648 | Oil & Gas Operator | Dec 1996 |
| 365 | Davenport Production Corp. | | Oil Operator | Sep 1988 |
| 366 | Davenport, Vernon | Shamrock, TX 79079 | Oil & Gas Operator | Mar 2008 |
| 367 | Davenport, Vernon Prod. Co. | Dumas, TX 79029 | Oil & Gas Operator | Jan 2002 |
| 368 | Davey Corporation | Golden, CO 80401 | Oil & Gas Operator | Jul 2026 |
| 369 | David A Waldron & Assoc | Wooster, OH 44691 | Oil & Gas Operator | Dec 2016 |
| 370 | David A. Robinson | | Oil Operator | Jan 1999 |
| 371 | David Crow | | Oil & Gas Operator | Nov 1985 |
| 372 | David D. Davis | Benton, KS 67017 | Oil Operator | Dec 2009 |
| 373 | David Divine Production | | Oil & Gas Operator | Nov 1997 |
| 374 | David E & Edna P Keller | Sugar Grove, PA 16350-5930 | Oil & Gas Operator | Dec 2009 |
| 375 | David E Morgan Inc | Danville, CA 94506-2035 | Oil & Gas Operator | May 2026 |
| 376 | David G Hammond | Artesia, NM 88211 | Oil Operator | May 2013 |
| 377 | David H Arrington Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Jul 2026 |
| 378 | David L Greene II LLC | | Oil Operator | May 2026 |
| 379 | David L Hill | Bradford, PA 16701-0309 | Oil & Gas Operator | Dec 2025 |
| 380 | David L. Whittington | | Gas Operator | Dec 1998 |
| 381 | David L. Whittington Inc | | Gas Operator | Sep 2022 |
| 382 | David Lesher Dba Lesher Oil | Reno, PA 16343-0293 | Oil Operator | Dec 2006 |
| 383 | David Lynn Chiles | | Oil & Gas Operator | Aug 2020 |
| 384 | David New Operating Co. Inc. | | Oil & Gas Operator | Feb 1999 |
| 385 | David New Operating-Belle Exp | | Oil Operator | Mar 1990 |
| 386 | David R Hill Inc | Byesville, OH 43723 | Oil & Gas Operator | Dec 2025 |
| 387 | David Radcliff | | Oil & Gas Operator | Dec 2014 |
| 388 | David Ridley Oil LLC | Tecumseh, OK 74873 | Oil Operator | May 2026 |
| 389 | David, Phillip | Lawrenceville, IL 62439 | Oil & Gas Operator | Sep 2026 |
| 390 | Davidson Energy Inc | Perry, OK 73077 | Oil & Gas Operator | May 2026 |
| 391 | Davidson Gene | Perry, OK 73077-0144 | Oil & Gas Operator | Aug 2014 |
| 392 | Davidson Oil & Gas LLC | Hays, KS 67601 | Oil Operator | Mar 2026 |
| 393 | Davidson Production Company, LLC | Bertram, TX 78605 | Oil Operator | Sep 2026 |
| 394 | Davidson Roger D | Clarendon, PA 16313-4532 | Oil & Gas Operator | Dec 2025 |
| 395 | Davidson, Dan | Ozona, TX 76943 | Oil & Gas Operator | Sep 2026 |
| 396 | Davidson, Grover R. | Bertram, TX 78605 | Oil & Gas Operator | Sep 2026 |
| 397 | Davidson, William A, & Jennifer I. | Westfield, NY 14787 | Gas Operator | Dec 2025 |
| 398 | Davies & Company Inc | Tulsa, OK 74114 | Oil & Gas Operator | Nov 2000 |
| 399 | Davimac Energy LLC | Stroud, OK 74079 | Oil & Gas Operator | Jun 2026 |
| 400 | Davis & Carr Energy Co. | Midland, TX 79702 | Oil & Gas Operator | Jun 1994 |