| 401 | Pmo | Garland, TX 75040 | Oil & Gas Operator | Feb 2018 |
| 402 | Powell, Gene Investments, Inc. | Longview, TX 75608 | Oil & Gas Operator | Apr 2024 |
| 403 | Powell, N. P. Estate | Tyler, TX 75702 | Oil & Gas Operator | Aug 1997 |
| 404 | Powell, N. P. Estate Partnership | Tyler, TX 75702 | Oil & Gas Operator | May 2002 |
| 405 | Pozo Resources, Inc | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 406 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2025 |
| 407 | Prince Properties, Inc. | Electra, TX 76360 | Oil & Gas Operator | Aug 2003 |
| 408 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 409 | Pro-Test, Inc. | Kilgore, TX 75663 | Oil Operator | Dec 2025 |
| 410 | Progas Properties, Inc. | New Braunfels, TX 78132 | Oil & Gas Operator | Dec 2025 |
| 411 | Proven Natural Resources LLC | Canton, TX 75103 | Oil & Gas Operator | Dec 2025 |
| 412 | Psi Production, Inc. | Tyler, TX 75702 | Gas Operator | Jan 1994 |
| 413 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 414 | Quanico Oil & Gas, Inc. | El Dorado, AR 71730 | Oil & Gas Operator | Dec 2025 |
| 415 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2025 |
| 416 | Quatros Operating Company | Kilgore, TX 75663 | Oil Operator | Dec 2025 |
| 417 | Quest Energies Group,LTD. | Shreveport, LA 71106 | Oil & Gas Operator | Mar 1997 |
| 418 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 419 | R & C Petroleum, Inc. | Flint, TX 75762 | Oil & Gas Operator | Dec 2025 |
| 420 | R2Q Operating LLC | Iowa Park, TX 76367 | Oil & Gas Operator | Dec 2025 |
| 421 | Ranger Investments, Inc. | Longview, TX 75605 | Oil & Gas Operator | Oct 2006 |
| 422 | Redwood Oil & Gas | McKinney, TX 75070 | Oil & Gas Operator | Apr 2013 |
| 423 | Refuge Properties, LLC | Longview, TX 75608 | Oil Operator | Mar 2025 |
| 424 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Dec 2025 |
| 425 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Dec 2025 |
| 426 | Reostar Operating Incorporated | Fort Worth, TX 76107 | Oil & Gas Operator | Sep 2012 |
| 427 | Reserve Management, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Dec 2025 |
| 428 | Reserve Production, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Mar 2008 |
| 429 | Reynolds Drilling Co., Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Dec 2025 |
| 430 | Reynolds E & P, Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Dec 2025 |
| 431 | Rheata Resources, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 432 | Richter Operating Company | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2007 |
| 433 | Rig Runner Express Inc Of Texas | Kilgore, TX 75663 | Oil & Gas Operator | May 2014 |
| 434 | Rig Runner Express, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Mar 2008 |
| 435 | Riverine, L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Nov 2021 |
| 436 | RLM Energy Company Inc. | Monroe, LA 71201 | Oil & Gas Operator | Mar 2008 |
| 437 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 438 | Rmor Production | Kilgore, TX 75662 | Oil Operator | Dec 2025 |
| 439 | Roach, R. Byron Trustee | Judson, TX 75660 | Oil & Gas Operator | Mar 1999 |
| 440 | Robbins Petroleum Corp. | Longview, TX 75606 | Oil & Gas Operator | Sep 1994 |
| 441 | Robertson Resources, Inc. | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Dec 2025 |
| 442 | Robertson-Bryce Management, LLC | Tyler, TX 75701 | Oil & Gas Operator | Dec 2025 |
| 443 | Robinett Resources Inc. | Longview, TX 75601 | Oil & Gas Operator | Dec 1999 |
| 444 | Rockcliff Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 445 | Rojo Burro Petroleo & Gas | Kilgore, TX 75662 | Oil & Gas Operator | Aug 2007 |
| 446 | Roosth & Genecov Production Co. | Tyler, TX 75710 | Oil & Gas Operator | Aug 2003 |
| 447 | Roosth Production Co. | Tyler, TX 75711 | Oil & Gas Operator | Dec 2025 |
| 448 | Royal Petroleum Corp. | Dallas, TX 75229 | Oil & Gas Operator | Jan 2025 |
| 449 | Rusk Co. Well Service Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 450 | Russell - FT. Trinidad Op., LLC | Tyler, TX 75710 | Oil & Gas Operator | Dec 2025 |
| 451 | RWS Operating Co. LLC | Kilgore, TX 75663 | Oil Operator | Dec 2025 |
| 452 | S N D Energy Company, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Dec 2025 |
| 453 | S.E.D.I. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2015 |
| 454 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 455 | Sabine Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 456 | Sabine Pipe & Supply Co. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2004 |
| 457 | Sabine Pipe, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 458 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 459 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 460 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 461 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2025 |
| 462 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2025 |
| 463 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Dec 2025 |
| 464 | Schlachter Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | Dec 2025 |
| 465 | Schlachter, David A. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2015 |
| 466 | Schlachter, David A., Estate Of | Dallas, TX 75225 | Oil & Gas Operator | Jan 2000 |
| 467 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Dec 2025 |
| 468 | SDG Operating Company, Inc | Tyler, TX 75701 | Oil & Gas Operator | Dec 2025 |
| 469 | Segrest-Ward Joint Venture | Longview, TX 75606 | Oil & Gas Operator | Jun 2001 |
| 470 | Sei Operating, LLC | Mandeville, LA 70471 | Oil & Gas Operator | Dec 2025 |
| 471 | Setex Oil And Gas Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2012 |
| 472 | Sheer Energy, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 473 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 474 | Shoco Production LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 475 | Shoco Production, L.P. | Kilgore, TX 75663 | Oil & Gas Operator | May 2020 |
| 476 | SHS Operating Company | Shreveport, LA 71149 | Oil & Gas Operator | Jan 2025 |
| 477 | Sigmon Construction Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 478 | Sigmon Production Company, Inc. | Longview, TX 75608 | Oil & Gas Operator | Dec 2013 |
| 479 | Signal Oil Company, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 480 | Silver Oak Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Dec 2009 |
| 481 | Silver Oak Operating, LLC | Longview, TX 75604 | Oil & Gas Operator | Dec 2025 |
| 482 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Sep 2025 |
| 483 | Sinclair Exploration Company | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 484 | Siroco Operating Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2010 |
| 485 | Sklar & Phillips Oil Co. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2000 |
| 486 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2025 |
| 487 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Dec 2025 |
| 488 | Smal Energy Corp | Tyler, TX 75710 | Oil & Gas Operator | Oct 1995 |
| 489 | Smith & Marrs Inc. | Lubbock, TX 79424 | Oil & Gas Operator | Apr 2021 |
| 490 | Smith Oil Co. | Smackover, AR 71762 | Oil Operator | Jan 2025 |
| 491 | Smith Operating & Management Co. | Shreveport, LA 71161 | Oil & Gas Operator | Feb 2005 |
| 492 | Smith Resources, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Dec 2025 |
| 493 | Smith Resources, L.L.C. | Marshall, TX 75671 | Oil & Gas Operator | Dec 2025 |
| 494 | Smith, E.N. III Energy Corp. | Marshall, TX 75671 | Oil & Gas Operator | Sep 2006 |
| 495 | Smith, R. E. Interests, Inc. | Houston, TX 77027 | Oil & Gas Operator | Mar 1998 |
| 496 | SND Operating, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 497 | Sonat Exploration Company -Tyler | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 498 | Sonat Exploration Company-MCR | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 499 | Southern Bay Operating, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 500 | Southlake Operating LLC | Weatherford, TX 76086 | Oil & Gas Operator | Dec 2025 |