| 301 | KCS Resources LLC | Houston, TX 77027 | Oil & Gas Operator | Feb 2017 |
| 302 | Kerr McGee Rocky MTN Corp | Denver, CO 80202-5736 | Oil & Gas Operator | Mar 2015 |
| 303 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Mar 2025 |
| 304 | Kiester Operating Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Jan 2025 |
| 305 | Kirkpatrick Oil Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Jun 2025 |
| 306 | Klo LLC | Tulsa, OK 74120-2428 | Oil & Gas Operator | Mar 2025 |
| 307 | Kolar Petroleum Inc | Oklahoma City, OK 73162-1509 | Oil & Gas Operator | Jun 2007 |
| 308 | Kopco, Inc. | Caney, KS 67333 | Oil & Gas Operator | Mar 2025 |
| 309 | KP Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1997 |
| 310 | KT Investments Inc | Hennessey, OK 73742 | Oil & Gas Operator | Mar 2025 |
| 311 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2025 |
| 312 | L & B Oil Company Inc | Houston, TX 77019-3115 | Oil & Gas Operator | Mar 2025 |
| 313 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | Feb 2025 |
| 314 | Lariat Petroleum Inc | Tulsa, OK 74119 | Oil & Gas Operator | Sep 2024 |
| 315 | Las Colinas Oil Corp. | Irving, TX 75062 | Oil & Gas Operator | Mar 2015 |
| 316 | Latigo Oil And Gas Inc | Woodward, OK 73801 | Oil & Gas Operator | Mar 2025 |
| 317 | LCB Resources LLC | Kingfisher, OK 73750-2322 | Oil & Gas Operator | Mar 2025 |
| 318 | Leeman Energy Corporation | Oklahoma City, OK 73118-1802 | Oil & Gas Operator | Mar 2015 |
| 319 | Legacy - M & K Corporation | Dallas, TX 75231-0969 | Oil & Gas Operator | Jan 2025 |
| 320 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Jun 2025 |
| 321 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Aug 2024 |
| 322 | Linn Mid-Continent Operating Inc | Houston, TX 77002-3018 | Oil & Gas Operator | Jun 2016 |
| 323 | Locin Oil Corporation | Katy, TX 77494 | Oil & Gas Operator | Jun 2025 |
| 324 | Lorentz Oil & Gas LLC | Edmond, OK 73034-7266 | Oil & Gas Operator | Feb 2025 |
| 325 | Lu-Ray Petroleum LLC | Oklahoma City, OK 73121-1607 | Oil & Gas Operator | Mar 2025 |
| 326 | M & D Pumping Service Inc | Ringwood, OK 73768-3415 | Oil & Gas Operator | Oct 2024 |
| 327 | M And V Resources Inc | Crescent, OK 73028 | Oil & Gas Operator | Feb 2025 |
| 328 | M M Energy, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Feb 2025 |
| 329 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | Jun 2025 |
| 330 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Mar 2025 |
| 331 | Mack Oil Company | Duncan, OK 73534 | Oil & Gas Operator | Nov 2000 |
| 332 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 333 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 334 | Manna Corporation | Oklahoma City, OK 73162 | Oil & Gas Operator | Dec 2014 |
| 335 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Mar 2025 |
| 336 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Apr 2025 |
| 337 | Marjo Operating Company Inc | Tulsa, OK 741010729 | Oil & Gas Operator | Feb 2025 |
| 338 | Marjo Operating Mid-Continent LLC | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2025 |
| 339 | Massad George H Estate | Holdenville, OK 74848 | Oil & Gas Operator | Dec 2014 |
| 340 | Maverick Oil Co. | Richland, TX 76681 | Oil Operator | Jun 2025 |
| 341 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 342 | McQueen Ed & Company Inc | Lindsey, OK 73052 | Oil & Gas Operator | Apr 2014 |
| 343 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 344 | Megaenergy Operating, Inc. | Edmond, OK 73034 | Oil & Gas Operator | Jul 2015 |
| 345 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Jun 2025 |
| 346 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 347 | Michigan Oil Co. | FT Worth, TX 76117 | Oil & Gas Operator | Feb 1998 |
| 348 | Mid-Con Central Expl Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2014 |
| 349 | Middle Bay Production Co. Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2014 |
| 350 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 351 | Midnight Hour LLC | Enid, OK 73702 | Oil & Gas Operator | Apr 2020 |
| 352 | Milburn R Kenneth | Ardmore, OK 73402-1118 | Oil & Gas Operator | Sep 2014 |
| 353 | Molz Oil Company | Kiowa, KS 67070 | Oil & Gas Operator | Mar 2025 |
| 354 | Monroe Natural Gas Inc | Norman, OK 73071 | Oil & Gas Operator | Feb 2025 |
| 355 | Monty L Hott Production Corporation | Oklahoma City, OK 73142 | Oil & Gas Operator | Feb 2025 |
| 356 | Moore Clay | Bradenton, FL 34211 | Oil & Gas Operator | Feb 2025 |
| 357 | Morrison International Energy Inc | Oklahoma City, OK 73189-0537 | Oil & Gas Operator | Feb 2025 |
| 358 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Jun 2025 |
| 359 | Muegge, Clay A. | Lamont, OK 74643 | Oil & Gas Operator | Mar 2025 |
| 360 | Muras Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | Feb 2025 |
| 361 | Murchison Oil & Gas Inc | Plano, TX 75024 | Oil & Gas Operator | Mar 2024 |
| 362 | Mustang Gas Products LLC | Oklahoma City, OK 73114-7406 | Oil & Gas Operator | Sep 2022 |
| 363 | National Energy Group, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 364 | Neg Operating LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | Nov 2024 |
| 365 | Neilson Inc | Nash, OK 73761 | Oil & Gas Operator | Aug 2022 |
| 366 | Nelco Oil & Gas | Duncan, OK 73533-1516 | Oil & Gas Operator | Oct 2015 |
| 367 | Nelson Exploration Corporation | Cleveland, OK 74020-5725 | Oil & Gas Operator | Jan 2025 |
| 368 | Nfcda Energy LLC | Edmond, OK 73013 | Oil & Gas Operator | Mar 2025 |
| 369 | Nielson & Associates Inc | Cody, WY 82414 | Oil & Gas Operator | Feb 2016 |
| 370 | Nordan Oil & Gas Corporation | Abilene, TX 79604 | Oil & Gas Operator | Feb 2018 |
| 371 | North Lake Resources LLC | Oklahoma City, OK 73132 | Oil & Gas Operator | Jun 2025 |
| 372 | Northwest Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Jun 2014 |
| 373 | O G & E | Oklahoma City, OK 73124 | Oil & Gas Operator | Feb 2014 |
| 374 | O K Swabbing Inc | Hennessey, OK 73742 | Oil & Gas Operator | Feb 2025 |
| 375 | Oklahoma Energy Acquisitions LP | Houston, TX 77094-1900 | Oil & Gas Operator | Jan 2025 |
| 376 | Oklahoma Oil & Gas MGMT Inc | Edmond, OK 73083-6786 | Oil & Gas Operator | Feb 2025 |
| 377 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 378 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Mar 2025 |
| 379 | Okmar Oil Company | Marietta, OH 45750 | Oil & Gas Operator | Jun 2005 |
| 380 | Okt Petroleum Company Inc | Oklahoma City, OK 73118-7425 | Oil & Gas Operator | Oct 2013 |
| 381 | Olympic Petroleum Company | Tulsa, OK 74114 | Oil & Gas Operator | Jun 1998 |
| 382 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 383 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 384 | Open Range Energy LLC | Jones, OK 73049-8744 | Oil & Gas Operator | Mar 2025 |
| 385 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Mar 2025 |
| 386 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 387 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Mar 2025 |
| 388 | Paleo, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Jun 2025 |
| 389 | Panadero Oil Company | Dallas, TX 75206 | Oil & Gas Operator | Apr 2002 |
| 390 | Panenergy Services Inc | Houston, TX 77525 | Oil & Gas Operator | May 2001 |
| 391 | Paradigm Petroleum Corporation | Abilene, TX 79605 | Oil & Gas Operator | Jun 2025 |
| 392 | Park Avenue Exploration Corp | Oklahoma City, OK 73102-5604 | Oil & Gas Operator | Sep 2011 |
| 393 | Parkway Petroleum, Inc. | Giddings, TX 78942 | Oil & Gas Operator | Jul 1997 |
| 394 | Parsons Engineering Corporation | Tulsa, OK 74137-7505 | Oil & Gas Operator | Oct 2017 |
| 395 | Partners Oil Company | Tulsa, OK 74135 | Oil & Gas Operator | Aug 1995 |
| 396 | Parwest Land Exploration, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2025 |
| 397 | Payrock Energy LLC | Oklahoma City, OK 73134-2612 | Oil & Gas Operator | Feb 2023 |
| 398 | Penner Energy Inc | Oklahoma City, OK 73120-1930 | Oil & Gas Operator | Mar 2025 |
| 399 | Penntex Resources, L.P. | State College, PA 16803 | Oil & Gas Operator | Mar 2016 |
| 400 | Petrocorp Incorporated | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2021 |