| 401 | Ladd Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2004 |
| 402 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | May 2026 |
| 403 | Lamb Alan L | Oklahoma City, OK 73120-7824 | Oil & Gas Operator | Feb 2020 |
| 404 | Lambdin William H | Oklahoma City, OK 73120 | Oil & Gas Operator | Nov 1998 |
| 405 | Lance Ruffel Oil & Gas LLC | Oklahoma City, OK 73102-5632 | Oil & Gas Operator | Jun 2026 |
| 406 | Lariat Energy & Supply Co Inc | Hulbert, OK 74441 | Oil & Gas Operator | Feb 2026 |
| 407 | Lariat Petroleum Inc | Tulsa, OK 74119 | Oil & Gas Operator | Sep 2024 |
| 408 | Lario Oil & Gas Company | Denver, CO 80206 | Oil & Gas Operator | Sep 2026 |
| 409 | Last Run, LLC | Rillito, AZ 85246 | Oil & Gas Operator | May 2020 |
| 410 | Latigo Drilling Corporation | Duncan, OK 73533 | Oil & Gas Operator | May 2026 |
| 411 | Laurco Energies,Inc | | Oil & Gas Operator | May 2025 |
| 412 | Laurel Operating Company | Stillwater, OK 74074-3025 | Oil & Gas Operator | May 2026 |
| 413 | LCB Resources LLC | Kingfisher, OK 73750-2322 | Oil & Gas Operator | Jun 2026 |
| 414 | Le Norman Energy Corporation | Duncan, OK 73534 | Oil & Gas Operator | Nov 2014 |
| 415 | Leavell Resources Corporation | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 416 | Leed Energy LLC | Purcell, OK 73080-1383 | Oil & Gas Operator | May 2026 |
| 417 | Leede Oil & Gas Inc. | Greenwood VLG, CO 80111 | Oil & Gas Operator | Aug 2003 |
| 418 | Liberty Operating Inc | Norman, OK 73069-8225 | Oil & Gas Operator | Dec 2024 |
| 419 | Lime Rock Resources A, L.P. | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 420 | Lime Rock Resources IV-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Sep 2026 |
| 421 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Jun 2025 |
| 422 | Long Resources Inc | Austin, TX 78730 | Oil & Gas Operator | Jun 2026 |
| 423 | Lorentz Oil & Gas LLC | Edmond, OK 73034-7266 | Oil & Gas Operator | May 2026 |
| 424 | LRR IV Operating Inc | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 425 | LX4, LLC | Gage, OK 73843 | Oil Operator | May 2026 |
| 426 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | Sep 2026 |
| 427 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Jun 2026 |
| 428 | Mack Oil Company | Duncan, OK 73534 | Oil & Gas Operator | Nov 2000 |
| 429 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | Jun 2026 |
| 430 | Magnum Energy Inc | Norman, OK 73072-2403 | Oil & Gas Operator | Jun 2026 |
| 431 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Jun 2026 |
| 432 | Marathon Oil Company LLC | Houston, TX 77079 | Oil & Gas Operator | Jun 2026 |
| 433 | Mark A Meier Dba MSC Oil And Gas Co | Oklahoma City, OK 73105 | Oil & Gas Operator | Jun 2026 |
| 434 | Mark L Shidler Inc | Houston, TX 77055 | Oil & Gas Operator | Jun 2026 |
| 435 | Marler Philip | Purcell, OK 73080-1522 | Oil & Gas Operator | Nov 2016 |
| 436 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | May 2026 |
| 437 | Marsh Operating Company | Dallas, TX 75221 | Oil & Gas Operator | Apr 2026 |
| 438 | Matador E & P Company Inc | | Oil & Gas Operator | May 2020 |
| 439 | Maverick Drilling Co., Inc. | Austin, TX 78729 | Oil & Gas Operator | Mar 2015 |
| 440 | Maxine Oil Company | Muskogee, OK 74401-0512 | Oil & Gas Operator | Sep 2014 |
| 441 | Maxwell Resources Corporation | Oklahoma City, OK 73159 | Oil & Gas Operator | Apr 2009 |
| 442 | May Petroleum Inc | Dallas, TX 75231 | Oil & Gas Operator | Nov 1998 |
| 443 | MBR Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Sep 2026 |
| 444 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | May 2026 |
| 445 | McQueen Ed & Company Inc | Lindsey, OK 73052 | Oil & Gas Operator | Apr 2014 |
| 446 | Meade Energy Corporation | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | Jun 2026 |
| 447 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Jun 2026 |
| 448 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 449 | Mep Operating LLC | Houston, TX 77056-2733 | Oil & Gas Operator | Aug 2025 |
| 450 | Meridian Oil Production Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 2024 |
| 451 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Sep 2026 |
| 452 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 453 | Metropolitan Resources Corp | Tulsa, OK 74169-1734 | Oil & Gas Operator | Mar 2015 |
| 454 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | Sep 2026 |
| 455 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 456 | Midwest Pipe & Supply Company | Oklahoma City, OK 73154-0245 | Oil & Gas Operator | Dec 2008 |
| 457 | Minerva Oil Company | Tulsa, OK 74152-0858 | Oil & Gas Operator | Mar 2015 |
| 458 | Mobil Exp & Prod Us Inc | Houston, TX 77060-1991 | Oil & Gas Operator | May 2001 |
| 459 | Mogo Operating, LLC | Norman, OK 73069 | Oil & Gas Operator | Jun 2026 |
| 460 | Monroe Natural Gas Inc | Norman, OK 73071 | Oil & Gas Operator | May 2026 |
| 461 | Moore & Moore Energy Inc | Purcell, OK 73080-0674 | Oil & Gas Operator | Dec 2012 |
| 462 | Moore Don | Elmore City, OK 73433 | Oil & Gas Operator | May 2026 |
| 463 | Moore Investments LC | Oklahoma City, OK 73116-9044 | Oil & Gas Operator | Feb 2023 |
| 464 | Moore Petroleum Invest Corp | Norman, OK 73072-4217 | Oil & Gas Operator | May 2026 |
| 465 | Moran-K Oil LLC | Seminole, OK 74868 | Oil & Gas Operator | Jun 2026 |
| 466 | Morgan Oil Company | Nacogdoches, TX 75963 | Oil & Gas Operator | May 2006 |
| 467 | Morgan Petroleum Company | Edmond, OK 73083 | Oil & Gas Operator | Mar 1993 |
| 468 | Mott Oil & Gas | Sugarland, TX 77478 | Oil & Gas Operator | May 2001 |
| 469 | Mott Petroleum Corporation | Sugar Land, TX 77487 | Oil & Gas Operator | Aug 2024 |
| 470 | Mullins Jimmy R Dba Southcreek Petroleum Co | Dibble, OK 73031 | Oil & Gas Operator | Jan 2021 |
| 471 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 472 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Sep 2026 |
| 473 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 474 | Nadel And Gussman LLC | Tulsa, OK 74119 | Oil & Gas Operator | Sep 2026 |
| 475 | National Cooperative RFG Assoc | McPherson, KS 67460-1404 | Oil & Gas Operator | Oct 2025 |
| 476 | National Oil Company | Garden City, KS 67846 | Oil & Gas Operator | Jun 2024 |
| 477 | Native Exploration Operating LLC | Oklahoma City, OK 73102-5804 | Oil & Gas Operator | Aug 2025 |
| 478 | Nbi Services, Inc. | Tulsa, OK 74159 | Oil & Gas Operator | Sep 2026 |
| 479 | Newkumet Exploration, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2020 |
| 480 | Nexco Inc | Oklahoma City, OK 73102-6801 | Oil & Gas Operator | Nov 2013 |
| 481 | Nfcda Energy LLC | Edmond, OK 73013 | Oil & Gas Operator | Jun 2026 |
| 482 | Nichols, Irl. A. Trust B | Duncan, OK 73534 | Oil & Gas Operator | Sep 2000 |
| 483 | Nielson & Associates, Inc | Cody, WY 82414 | Oil & Gas Operator | Feb 2016 |
| 484 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Sep 2026 |
| 485 | Noble Energy Production Inc | Houston, TX 77067 | Oil & Gas Operator | Sep 2026 |
| 486 | Nomoc Oil Company Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | May 2006 |
| 487 | North American Royalties, Inc. | Chattanooga, TN 37408 | Oil & Gas Operator | Oct 2001 |
| 488 | Northwest Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Jun 2014 |
| 489 | Novo II Operating, LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | May 2026 |
| 490 | O G & E | Oklahoma City, OK 73124 | Oil & Gas Operator | Feb 2014 |
| 491 | O'Neal Oil & Gas Co | Fort Worth, TX 76107-1479 | Oil & Gas Operator | Jun 2026 |
| 492 | Obele Operating Company LLC | Sedona, AZ 86336-5745 | Oil & Gas Operator | May 2026 |
| 493 | Ofs-Tulsa Corporation | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 1997 |
| 494 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | Sep 2026 |
| 495 | Oil Recovery Systems Inc | Tulsa, OK 74145-4619 | Oil & Gas Operator | May 2026 |
| 496 | Oilfield Operating Company | Cushing, OK 74023-1347 | Oil & Gas Operator | Jan 2018 |
| 497 | Oklahoma Equipment & Salvage | Oklahoma City, OK 73120-5903 | Oil & Gas Operator | Mar 2015 |
| 498 | Oklahoma Oil & Gas MGMT Inc | Edmond, OK 73083-6786 | Oil & Gas Operator | Apr 2026 |
| 499 | Oklahoma Prime Energy LLC | Ardmore, OK 73401 | Oil Operator | May 2020 |
| 500 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Jun 2026 |