| 301 | D C Oil Company, Inc. | Sundown, TX 79372 | Oil & Gas Operator | Mar 2026 |
| 302 | D&D Energy Company | N.Canton, OH 44721 | Oil & Gas Operator | Dec 2020 |
| 303 | D-D Oil | Woodsfield, OH 43793 | Oil & Gas Operator | Dec 2018 |
| 304 | D. G. Oil Co. | Dennis, TX 76439 | Oil & Gas Operator | Mar 2026 |
| 305 | Dalton & Hanna LTD | Wooster, OH 44691 | Oil & Gas Operator | Dec 2018 |
| 306 | Danny Long & Sons Inc | Magnolia, OH 44643 | Oil & Gas Operator | Dec 2024 |
| 307 | Dart Oil & Gas Corporation | Mason, MI 48854 | Oil & Gas Operator | Jun 2018 |
| 308 | Dart Oil & Gas Ohio LLC | Mason, MI 48854 | Oil Operator | Dec 2018 |
| 309 | Dart Oil Company | Parker, CO 80134 | Oil & Gas Operator | Dec 2024 |
| 310 | David A Waldron & Assoc | Wooster, OH 44691 | Oil & Gas Operator | Dec 2016 |
| 311 | David R Hill Inc | Byesville, OH 43723 | Oil & Gas Operator | Dec 2024 |
| 312 | Davis Bradley & Kathy | Stockport, OH 43787 | Oil Operator | Dec 2024 |
| 313 | DC Oil & Gas LLC | Woodsfield, OH 43793 | Oil & Gas Operator | Dec 2024 |
| 314 | Dci Petroleum Inc | University Heights, OH 44118-3818 | Oil & Gas Operator | Dec 2017 |
| 315 | Decker Well Service LLC | Fleming, OH 45729 | Oil & Gas Operator | Dec 2017 |
| 316 | Decleva, Paul | Wichita Falls, TX 76302 | Oil & Gas Operator | Dec 2020 |
| 317 | Deep Resources LLC | Holmesville, OH 44633 | Oil & Gas Operator | Dec 2023 |
| 318 | Deer Creek Inc | Cambridge, OH 43725 | Oil & Gas Operator | Dec 2019 |
| 319 | Deer Oil & Gas | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 320 | Delta Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2024 |
| 321 | Dennis Lloyd D | Fleming, OH 45729 | Oil & Gas Operator | Dec 2024 |
| 322 | Dennis Oil & Gas LLC | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2024 |
| 323 | Depuy Drilling Co | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 324 | Derby Oil & Gas Corp | Cumberland, OH 43732 | Oil & Gas Operator | Dec 1986 |
| 325 | Derby Operating Corp | Wooster, OH 44691 | Oil & Gas Operator | Dec 2024 |
| 326 | Derrick Petroleum Inc | Bladensburg, OH 43005 | Oil & Gas Operator | Dec 2024 |
| 327 | Desco Corp | Columbus, OH 43085 | Oil & Gas Operator | Dec 1989 |
| 328 | Dever Lavon B | Cambridge, OH 43725 | Oil & Gas Operator | Dec 2012 |
| 329 | Dever Linda K | Norwalk, OH 43767 | Oil & Gas Operator | Dec 2024 |
| 330 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2026 |
| 331 | Devon Petroleum Corp. | Marietta, OH 45750 | Oil & Gas Operator | Dec 1996 |
| 332 | Devore Anthony D | Gambier, OH 43022 | Oil & Gas Operator | Dec 2010 |
| 333 | Diamond Oil Co | Lancaster, OH 43130 | Oil & Gas Operator | Dec 1992 |
| 334 | Diamond Shamrock Chem Co | Irving, TX 75061 | Oil & Gas Operator | Dec 1990 |
| 335 | Dietrich Foundation | Pittsburgh, PA 15219 | Gas Operator | Dec 2024 |
| 336 | Dietrich Philip H | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2024 |
| 337 | Dietz Oil Field Supply | Dover, OH 44622 | Oil & Gas Operator | Dec 1997 |
| 338 | Dils Oil & Gas | Parkersburg, WV 26101 | Oil & Gas Operator | Dec 2024 |
| 339 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | Mar 2026 |
| 340 | Discovery Oil And Gas | Canonburg, PA 15317 | Oil & Gas Operator | Dec 2024 |
| 341 | Discovery Oil LTD | Los Angeles, CA 90067 | Oil & Gas Operator | Jan 1993 |
| 342 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Mar 2026 |
| 343 | Dixon Exploration Inc | Abilene, TX 79604 | Oil & Gas Operator | Oct 2019 |
| 344 | DJR Well Services Inc | McDonald, OH 44437 | Oil & Gas Operator | Dec 2025 |
| 345 | DNL Oil Corp | New Lexington, OH 43764 | Oil & Gas Operator | Dec 2012 |
| 346 | Dome Drilling Co | Westlake, OH 44145-1964 | Oil & Gas Operator | Dec 2009 |
| 347 | Dome Producing | Cleveland, OH 44114 | Oil & Gas Operator | Dec 1988 |
| 348 | Domestic Oil & Gas Co | Bedford, OH 44146 | Oil & Gas Operator | Dec 1990 |
| 349 | Dominion East Ohio | North Canton, OH 44720 | Oil & Gas Operator | Dec 2023 |
| 350 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 351 | Dominion Field Services Inc | Richmond, VA 23219 | Oil & Gas Operator | Dec 2013 |
| 352 | Don Byers Oil & Gas LLC | Heath, OH 43056 | Oil & Gas Operator | Dec 2024 |
| 353 | Don Yohe Enterprises Inc. | Armada, MI 48005 | Oil & Gas Operator | Apr 2018 |
| 354 | Donaker Alan M | Warsaw, OH 43844 | Oil & Gas Operator | Dec 1994 |
| 355 | Doran & Associates | Pittsburgh, PA 15220 | Oil & Gas Operator | Dec 1988 |
| 356 | Dorfman Production Company | Beloit, OH 44609 | Oil & Gas Operator | Mar 2026 |
| 357 | Dorsey Oil & Gas LLC | Nashport, OH 43830 | Oil & Gas Operator | Dec 2024 |
| 358 | Dover Atwood Corp. | Massillon, OH 44646 | Oil & Gas Operator | Dec 2024 |
| 359 | Dover Oil Co | Marietta, OH 45750 | Oil & Gas Operator | Dec 1999 |
| 360 | Drillex Inc | Mentor, OH 44060 | Oil & Gas Operator | Dec 2003 |
| 361 | Dry Hole Producing LLC | Poland, OH 44514 | Oil & Gas Operator | Dec 2024 |
| 362 | Dry Hole Producing LP | Poland, OH 44514-3631 | Oil & Gas Operator | Dec 2019 |
| 363 | Duck Creek Energy Inc | Brecksville, OH 44141 | Oil & Gas Operator | Dec 2024 |
| 364 | Duck Creek Petroleum LLC | Wooster, OH 44691 | Oil & Gas Operator | Dec 2012 |
| 365 | Dugan Evan | Martinsburg, OH 43037 | Oil & Gas Operator | Dec 2024 |
| 366 | Dugan Guy E | Walhonding, OH 43843 | Oil & Gas Operator | Dec 2015 |
| 367 | Dugan Harry Oil Co | Newark, OH 43055 | Oil & Gas Operator | Dec 1993 |
| 368 | Dugan Oil And Gas LLC | Walhonding, OH 43843-9612 | Oil & Gas Operator | Dec 2024 |
| 369 | Dupke Roger Oil Co Inc | Reno, OH 45773 | Oil & Gas Operator | Dec 2004 |
| 370 | Durst Oil & Gas, Inc. | Point Pleasant, WV 25550 | Oil & Gas Operator | Dec 2021 |
| 371 | Dustin Energy Inc | Warren, OH 44481 | Oil & Gas Operator | Dec 2024 |
| 372 | Dusty Drilling & Producing Corp | New Lexington, OH 43764-1552 | Oil & Gas Operator | Dec 2005 |
| 373 | Duty Oil & Gas Prod Co | Akron, OH 44306 | Oil & Gas Operator | Dec 1997 |
| 374 | Dye Walter M | Woodsfield, OH 43793 | Oil & Gas Operator | Dec 2022 |
| 375 | E I C Inc | Coshocton, OH 43812 | Oil & Gas Operator | Dec 1984 |
| 376 | Eagle Expl Co/Johnson J | Bolivar, OH 44612 | Oil & Gas Operator | Dec 1989 |
| 377 | Eagle Mountain Energy | Columbus, OH 43214 | Oil & Gas Operator | Dec 2002 |
| 378 | Eap Ohio LLC | Oklahoma City, OK 73134-2646 | Oil & Gas Operator | Sep 2025 |
| 379 | Earley Donald E | Utica, OH 43080 | Oil Operator | Dec 2019 |
| 380 | Eastern Amer Energy Corp | Charleston, WV 25304 | Oil & Gas Operator | Dec 2006 |
| 381 | Eastern Mountain Fuel Inc | Marietta, OH 45750-1240 | Oil & Gas Operator | Dec 2002 |
| 382 | Eastern Petroleum Company | Girard, OH 44420 | Oil & Gas Operator | Sep 1995 |
| 383 | Eastern States Oil & Gas, Inc. | Ravenna, OH 44266 | Oil & Gas Operator | Dec 2020 |
| 384 | Eastland Energy Group Inc | Byesville, OH 43723 | Oil & Gas Operator | Dec 2024 |
| 385 | Echo Drilling Inc | Dover, OH 43622 | Oil & Gas Operator | Dec 2024 |
| 386 | Eclipse Resources I LP | Spring, TX 77389 | Oil & Gas Operator | Dec 2021 |
| 387 | Eclipse Resources-Ohio LLC | Morgantown, WV 26508 | Oil & Gas Operator | Dec 2020 |
| 388 | Eco Production LLC | Wooster, OH 44691-4683 | Oil & Gas Operator | Dec 2024 |
| 389 | Edco Drilling & Producing | MT Gilead, OH 43338 | Oil & Gas Operator | Dec 2006 |
| 390 | Eei Inc | MT Pleasant, MI 48858 | Oil & Gas Operator | Dec 1990 |
| 391 | Elan Energy Inc | Toledo, OH 43604-1207 | Oil & Gas Operator | Dec 1990 |
| 392 | Elba Oil Company LLC | Macksburg, OH 45746 | Oil Operator | Dec 2024 |
| 393 | Elephant Exploration Inc. | Hartville, OH 44632 | Oil & Gas Operator | Dec 2024 |
| 394 | Elk Oil Co LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2018 |
| 395 | Elkhead Gas & Oil Co | Newark, OH 43055 | Oil & Gas Operator | Dec 2024 |
| 396 | Ellen P Sharp LLC | Zanesville, OH 43701 | Oil & Gas Operator | Dec 2024 |
| 397 | Ellvie Wells LLC | New Franklin, OH 44319 | Oil & Gas Operator | Dec 2024 |
| 398 | Elsaan Energy LLC | Walhonding, OH 43843 | Oil & Gas Operator | Dec 2023 |
| 399 | Em Energy Ohio LLC | Canonsburg, PA 15317 | Oil & Gas Operator | Sep 2019 |
| 400 | Embassy Energy Inc. | Akron, OH 44333-8357 | Oil & Gas Operator | Dec 2024 |