| 401 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 402 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 403 | Oxxn | Weatherford, TX 76086 | Oil & Gas Operator | Oct 2023 |
| 404 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Feb 2026 |
| 405 | P. L. O. | Boerne, TX 78006 | Oil & Gas Operator | Jun 2016 |
| 406 | Panamerican Operating Inc | Dallas, TX 75219 | Oil & Gas Operator | Feb 2026 |
| 407 | Panhandle Oil & Gas Inc | Oklahoma City, OK 73112-5688 | Oil & Gas Operator | May 2007 |
| 408 | Pantex Oil & Gas LLC | Ranger, TX 76470 | Oil & Gas Operator | Jul 2018 |
| 409 | Panther Creek Resources, LLC | Denver, CO 80202 | Oil & Gas Operator | May 2012 |
| 410 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 411 | Patton Exploration, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 412 | Peak Flow Operating&Drilling LP | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2011 |
| 413 | Peak Natural Gas Co., LLC | Dallas, TX 75225 | Oil & Gas Operator | Sep 2010 |
| 414 | Peba Oil & Gas Co. | Wichita Falls, TX 76302 | Oil & Gas Operator | Jun 2015 |
| 415 | Peba Oil & Gas, Inc. | Nocona, TX 76255 | Oil & Gas Operator | Feb 2026 |
| 416 | Pecos Valley Management Co. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2008 |
| 417 | Penny, Ralph E. | White Plains, NY 10601 | Oil & Gas Operator | Jul 2023 |
| 418 | Peterson Oil And Gas LLC | Wichita Falls, TX 76310 | Oil & Gas Operator | Feb 2026 |
| 419 | Petex | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2026 |
| 420 | Petrogas Energy Services, LLC | Dallas, TX 75214 | Oil Operator | Feb 2026 |
| 421 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 422 | Pinewood Exploration Inc. | Arlington, TX 76096 | Oil & Gas Operator | Oct 2011 |
| 423 | Pioneer Exploration Company | Houston, TX 77090 | Oil & Gas Operator | Dec 2025 |
| 424 | Pioneer Exploration, LLC | Houston, TX 77090 | Oil & Gas Operator | Dec 2025 |
| 425 | Pioneer Exploration, LTD. | Houston, TX 77090 | Oil & Gas Operator | Sep 2008 |
| 426 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Feb 2026 |
| 427 | Plains Marketing, LP | Cushing, OK 74023 | Oil Operator | Jan 2012 |
| 428 | Pop Operating Company | Denton, TX 76202 | Oil & Gas Operator | Feb 2026 |
| 429 | Precise Development, Inc. | Austin, TX 78709 | Oil & Gas Operator | May 2005 |
| 430 | Precision Operating Inc. | Richardson, TX 75080 | Oil & Gas Operator | Jul 2014 |
| 431 | Premier Natural Resources II,LLC | Tulsa, OK 74105 | Oil & Gas Operator | Feb 2015 |
| 432 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2026 |
| 433 | Primexx Operating Corporation | Dallas, TX 75206 | Oil & Gas Operator | Mar 2024 |
| 434 | Primrose Operating Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Jun 2007 |
| 435 | Pursley, John | Jacksboro, TX 76458 | Oil & Gas Operator | Feb 2026 |
| 436 | Quail Ridge Petroleum LLC | Midland, TX 79710 | Oil & Gas Operator | Feb 2026 |
| 437 | Quatro Oil And Gas, Inc. | Joshua, TX 76058 | Oil & Gas Operator | Feb 2026 |
| 438 | Quest Petroleum Company | Jacksboro, TX 76458 | Oil & Gas Operator | Feb 2026 |
| 439 | Quest Petroleum, Inc. | Abilene, TX 79603 | Oil & Gas Operator | Feb 2026 |
| 440 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 441 | Ranger Operating Co. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 442 | Reddirt Operating, LLC. | Midland, TX 79704 | Oil & Gas Operator | Feb 2026 |
| 443 | Regal Energy Operating, L.L.C. | Plano, TX 75024 | Oil & Gas Operator | Feb 2026 |
| 444 | Reichmann Petroleum Corp. | Grapevine, TX 76051 | Oil & Gas Operator | Feb 2026 |
| 445 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Feb 2026 |
| 446 | Renaissance Petroleum Co LLC | Houston, TX 77058 | Oil & Gas Operator | Nov 2011 |
| 447 | Republic Energy Inc. | Decatur, TX 76234 | Oil & Gas Operator | Dec 2016 |
| 448 | Revier, J. B. Prod. Company | Wichita Falls, TX 76302 | Oil & Gas Operator | Apr 1996 |
| 449 | Rhyne, J.V. | Cisco, TX 76437 | Oil & Gas Operator | Feb 2026 |
| 450 | Richey, Ray Management Co., Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Feb 2026 |
| 451 | Rife Energy Operating, Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Feb 2026 |
| 452 | Rife Oil Properties Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Feb 2026 |
| 453 | Rimrock Energy, LLC | Fort Worth, TX 76147 | Oil & Gas Operator | Oct 2012 |
| 454 | Rivercity Operating, Inc. | Austin, TX 78766 | Oil & Gas Operator | Feb 2026 |
| 455 | RKW Operating LLC | Weatherford, TX 76085 | Gas Operator | Feb 2026 |
| 456 | Roberson, Joe | Vernon, TX 76385 | Oil & Gas Operator | Feb 2015 |
| 457 | Robinson Oil & Gas, Inc. | Chico, TX 76431 | Oil & Gas Operator | Aug 2003 |
| 458 | Roca Resource Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 459 | Rock Petroleum, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 460 | Rodgers, William L. | Fort Worth, TX 76147 | Oil & Gas Operator | Jan 1995 |
| 461 | Roil Mineral & Land Co. | Dallas, TX 75379 | Oil & Gas Operator | Feb 2026 |
| 462 | Rollo Resources, LLC | Granbury, TX 76049 | Gas Operator | Feb 2026 |
| 463 | Ropa Exploration Corp. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2011 |
| 464 | Ropar Operating Co. | Wichita Falls, TX 76301 | Oil & Gas Operator | Feb 2026 |
| 465 | Rose Exploration, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Feb 2002 |
| 466 | Rosehill Operating Company, LLC | Houston, TX 77084 | Oil & Gas Operator | Sep 2021 |
| 467 | Roseland Oil & Gas Inc | Rockwall, TX 75087 | Oil & Gas Operator | Feb 2003 |
| 468 | Ross, Dwight M. DRLG. Co., Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Feb 2026 |
| 469 | Routh Operating, LLC | Dallas, TX 75204 | Oil & Gas Operator | Mar 2011 |
| 470 | Rubicon Energy, L.L.C. | Arlington, TX 76006 | Oil & Gas Operator | Sep 1999 |
| 471 | Rubis Oil, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Feb 2026 |
| 472 | Rudman Partnership, The | Dallas, TX 75201 | Oil & Gas Operator | Dec 2014 |
| 473 | Rwa, LLC | Boyd, TX 76023 | Oil & Gas Operator | Feb 2026 |
| 474 | Ryder Scott Management, LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 2018 |
| 475 | Ryder Scott Oil Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2005 |
| 476 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 477 | S&G Oil LLC | Wichita Falls, TX 76309 | Oil & Gas Operator | Feb 2026 |
| 478 | Sabio Oil & Gas Inc. | Dallas, TX 75206 | Oil & Gas Operator | Jan 1998 |
| 479 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 480 | Saddle Creek Energy Development | Dallas, TX 75251 | Oil & Gas Operator | Nov 2008 |
| 481 | Sage Natural Resources LLC | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2026 |
| 482 | Sage Oil And Gas, LLC | Graham, TX 76450 | Gas Operator | Feb 2026 |
| 483 | Saguaro Petroleum, LLC | Midland, TX 79705 | Oil & Gas Operator | Feb 2026 |
| 484 | Sanco Operating Company | Bullard, TX 75757 | Oil & Gas Operator | Feb 2026 |
| 485 | Sanders Oil & Gas, LTD. | Granbury, TX 76048 | Oil & Gas Operator | Aug 2015 |
| 486 | Sauder Management Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 487 | Schalk Oil Company, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 488 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Feb 2026 |
| 489 | Seely Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |
| 490 | Shakespeare Oil Co Inc | Salem, IL 62881 | Oil & Gas Operator | Dec 2025 |
| 491 | Share Petroleum Corp. | Mabank, TX 75147 | Oil Operator | Feb 2026 |
| 492 | Shiloh Oil Company LLC | Williston, FL 32696 | Oil & Gas Operator | Feb 2026 |
| 493 | Siegfried R H Inc | Tulsa, OK 74104 | Oil & Gas Operator | Mar 2008 |
| 494 | Silver Creek Oil & Gas, LLC | Flower Mound, TX 75022 | Oil & Gas Operator | Feb 2026 |
| 495 | Silver Creek Resources, LLC | Irving, TX 75038 | Oil & Gas Operator | Apr 2017 |
| 496 | Slate Holdings, Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Feb 2026 |
| 497 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 498 | Snow Operating Co., Inc. | Haltom City, TX 76117 | Oil & Gas Operator | Feb 2024 |
| 499 | Somerset Operating, LLC | Weatherford, TX 76086 | Gas Operator | Feb 2026 |
| 500 | Sonat Exploration Company -Tyler | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |