| 401 | Incline Energy | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 402 | Inject Technologies Inc. | Andrews, TX 79714 | Oil Operator | May 2025 |
| 403 | Ip Petroleum Company, Inc. | Houston, TX 77210 | Oil & Gas Operator | Mar 2008 |
| 404 | Ipt Oil Company | Evansville, IN 47706 | Oil & Gas Operator | May 2025 |
| 405 | J-E Production, Inc. | Midland, TX 79708 | Oil & Gas Operator | Mar 2008 |
| 406 | J. D. Gas, Inc. | Stephenville, TX 76401 | Oil & Gas Operator | May 2025 |
| 407 | Jasmar Oil Co. | Levelland, TX 79336 | Oil & Gas Operator | Mar 2008 |
| 408 | Jaxploration Company L.C. | Andrews, TX 79714 | Oil & Gas Operator | Dec 1995 |
| 409 | Jetta Operating Company Inc | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 410 | Jim-Bob Oil Company | San Angelo, TX 76901 | Oil & Gas Operator | Dec 2003 |
| 411 | JM Cox Resources LP | Midland, TX 79702 | Oil & Gas Operator | Apr 2019 |
| 412 | Jones, Charles E., Jr. | Odessa, TX 79760 | Oil & Gas Operator | Jul 2013 |
| 413 | Journey Operating, L.L.C. | Sugar Land, TX 77496 | Oil & Gas Operator | Aug 2006 |
| 414 | JTL Operating Co Inc | Katy, TX 77450 | Oil & Gas Operator | May 2025 |
| 415 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | May 2025 |
| 416 | Karico GP, LLC | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 417 | Kem Energy, Inc. | Katy, TX 77450 | Oil & Gas Operator | May 2025 |
| 418 | Kemper Operating Co. | Abilene, TX 79605 | Oil & Gas Operator | Nov 2015 |
| 419 | Kendrick Oil And Gas Company | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 420 | Kenworthy Oil Company | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 421 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Mar 2025 |
| 422 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 423 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 424 | Key Energy Services, LLC | Houston, TX 77042 | Oil Operator | Jan 2025 |
| 425 | Kidd Oil & Gas, LC | Dallas, TX 75219 | Oil & Gas Operator | Apr 1999 |
| 426 | Kimbell Oil Company Of Texas | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2025 |
| 427 | Kimbrough Engineering Co, LLC | New Braunfels, TX 78132 | Oil & Gas Operator | Dec 2014 |
| 428 | Kinder Morgan Production Co LP | Midland, TX 79701 | Oil & Gas Operator | Jul 2007 |
| 429 | Kinlaw Oil Corporation | Dallas, TX 75380 | Oil & Gas Operator | May 2025 |
| 430 | Kinney Incorporated | Andrews, TX 79714 | Oil & Gas Operator | May 2025 |
| 431 | La VIda Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 1993 |
| 432 | Lakeshore Operating, LLC | Wichita, KS 67203 | Oil & Gas Operator | May 2025 |
| 433 | Lanexco, Inc. | Sealy, TX 77474 | Oil & Gas Operator | May 2025 |
| 434 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | May 2025 |
| 435 | Latigo Petroleum Texas, LP | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 436 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | May 2025 |
| 437 | Leonard Brothers Operating Co. | Fort Worth, TX 76101 | Oil & Gas Operator | May 2025 |
| 438 | Libertad Operating LLC | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 439 | Limark Corporation | Midland, TX 79702 | Oil & Gas Operator | Dec 2003 |
| 440 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Feb 2025 |
| 441 | Lime Rock Resources IV-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 442 | Limestone Exploration II, LLC | Midland, TX 79704 | Oil & Gas Operator | Jun 2019 |
| 443 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Aug 2024 |
| 444 | Linn Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 445 | Linn Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2017 |
| 446 | Lion Production, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2006 |
| 447 | Live Oak Gas Company | Dallas, TX 75251 | Oil & Gas Operator | May 2025 |
| 448 | LNH Oil Company | Midland, TX 79708 | Oil & Gas Operator | Jan 2006 |
| 449 | Loin Energy Corporation | La Grange, TX 78945 | Oil & Gas Operator | May 2025 |
| 450 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 451 | Lothian Oil Texas I, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Mar 2008 |
| 452 | Lumbley, W. F. | Hobbs, NM 88242 | Oil & Gas Operator | Jan 2008 |
| 453 | Lynx Energy Company, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 454 | Lynx Operating Co., Inc. | Dallas, TX 75206 | Oil & Gas Operator | May 2025 |
| 455 | Lynx Petroleum Consultants Inc. | Hobbs, NM 88241 | Oil & Gas Operator | Feb 2024 |
| 456 | LZB Energy, LLC | Austin, TX 78737 | Gas Operator | Jul 2020 |
| 457 | LZS Corporation | Tulsa, OK 74105 | Oil & Gas Operator | Jan 2007 |
| 458 | M & M Production LTD. | Midland, TX 79704 | Oil & Gas Operator | May 2025 |
| 459 | M-C Production & Drilling Co,Inc | Longview, TX 75608 | Oil & Gas Operator | May 2025 |
| 460 | M-T Petroleum, Inc. | Andrews, TX 79714 | Oil & Gas Operator | Mar 2008 |
| 461 | M. P. S. Prod. Co. | Houston, TX 77225 | Oil & Gas Operator | Dec 1996 |
| 462 | Mack Energy Corporation | Artesia, NM 88211 | Oil & Gas Operator | Feb 2025 |
| 463 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | May 2025 |
| 464 | Mammoth Exploration LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2023 |
| 465 | Manning, Jack | Odessa, TX 79760 | Oil & Gas Operator | Dec 2003 |
| 466 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 467 | Maralo, LLC | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 468 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Mar 2025 |
| 469 | Mariah Energy Corp. | Austin, TX 78716 | Oil & Gas Operator | Apr 1999 |
| 470 | Marshall & Winston, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 471 | Marshall Petroleum, Inc. | Houston, TX 77040 | Oil & Gas Operator | Aug 2003 |
| 472 | Matador Drilling Corp. | Midland, TX 79708 | Oil & Gas Operator | Mar 1995 |
| 473 | Matador Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2003 |
| 474 | Maverick Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 475 | Maverick Permian LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 476 | Maxus Exploration Company | Dallas, TX 75201 | Oil & Gas Operator | Jan 1995 |
| 477 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 478 | McCabe Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2009 |
| 479 | McClure Oil Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 480 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | May 2025 |
| 481 | McDonnold Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 482 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 483 | McFarland & Scobey, Inc. | El Paso, TX 79947 | Oil & Gas Operator | May 2025 |
| 484 | McRae & Henry LTD | Golden, CO 80401 | Oil & Gas Operator | May 2022 |
| 485 | McShane, J. Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2004 |
| 486 | MDC Operating, Inc. | Midland, TX 79708 | Oil & Gas Operator | Oct 2022 |
| 487 | Me-Tex Oil & Gas, Inc. | Hobbs, NM 88241 | Oil & Gas Operator | May 2025 |
| 488 | Me-Tex Supply Company | Hobbs, NM 88240 | Oil & Gas Operator | Jun 1993 |
| 489 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 490 | Memorial Exploration Company | Saint Louis, MO 63105 | Oil & Gas Operator | Aug 1996 |
| 491 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 492 | Mercury Operating, LLC | Dallas, TX 75208 | Oil & Gas Operator | May 2025 |
| 493 | Meridian Exploration Corp. | Pittsburgh, PA 15222 | Oil & Gas Operator | Dec 2021 |
| 494 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 495 | Meridian Oil Inc.-Midland | Midland, TX 79702 | Oil & Gas Operator | Jul 1996 |
| 496 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 497 | Merrico Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2008 |
| 498 | Merritt Operating, Inc. | Mineola, TX 75773 | Oil & Gas Operator | May 2025 |
| 499 | Merritt, William Kevin | Dallas, TX 75225 | Oil & Gas Operator | Dec 1994 |
| 500 | Mesquite SWD Inc | Carlsbad, NM 88221 | Oil & Gas Operator | May 2025 |