| 401 | Questa Energy Corporation | Amarillo, TX 79159 | Oil & Gas Operator | Apr 2024 |
| 402 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 403 | R & A Moore, Inc. | Cleburne, TX 76033 | Oil & Gas Operator | Apr 2024 |
| 404 | R.E.D. Resources, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Apr 2004 |
| 405 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 406 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 2024 |
| 407 | Ranjan, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Apr 2024 |
| 408 | Raydon Exploration, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2024 |
| 409 | Red Earth Oil & Gas, Inc. | Oklahoma City, OK 73159 | Oil & Gas Operator | Oct 2021 |
| 410 | Red Line Company, LTD. | Pampa, TX 79066 | Oil & Gas Operator | Apr 2024 |
| 411 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 412 | Remnant Energy, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Apr 2024 |
| 413 | Remora Operating, LLC | Houston, TX 77056 | Oil & Gas Operator | Apr 2024 |
| 414 | Reneau, James Seed Co. | Shamrock, TX 79079 | Oil & Gas Operator | Apr 2024 |
| 415 | Resource Oil And Gas, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2024 |
| 416 | Revolution Operating Company,LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2024 |
| 417 | Riata Energy Inc | Oklahoma City, OK 73101 | Oil & Gas Operator | Apr 2008 |
| 418 | Ricks Expl Acquisition Corp | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2004 |
| 419 | Ricks Expl Acquisition LLC | Midland, TX 79701 | Oil & Gas Operator | Aug 2013 |
| 420 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 421 | Ricks Exploration, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2008 |
| 422 | Rife Energy Operating, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | Apr 2024 |
| 423 | Rife Oil Properties Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Apr 2024 |
| 424 | Rio Petroleum, Inc. | Amarillo, TX 79102 | Oil & Gas Operator | Apr 2024 |
| 425 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | Feb 2024 |
| 426 | Robin Of Perryton Corporation | Perryton, TX 79070 | Oil & Gas Operator | Apr 2024 |
| 427 | Robin Of Perryton, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Dec 1995 |
| 428 | Rockford Panhandle, LLC | Tulsa, OK 74105 | Oil & Gas Operator | Sep 2008 |
| 429 | Roemer Oil Company | Denver, CO 80202 | Oil & Gas Operator | Nov 1998 |
| 430 | Rosetta Resources Operating LP | San Antonio, TX 78216 | Oil & Gas Operator | Apr 2024 |
| 431 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Apr 2024 |
| 432 | Ryann Operating, LLC | Waller, TX 77484 | Oil & Gas Operator | Apr 2024 |
| 433 | Sabine Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 434 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 435 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 436 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 437 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2024 |
| 438 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 439 | San Marco Petroleum Inc | Denver, CO 80293 | Oil & Gas Operator | Jan 2024 |
| 440 | Sandlot Oil & Gas LLC | Gruver, TX 79040 | Oil & Gas Operator | Apr 2024 |
| 441 | Santa Fe Energy Oper. Part., LP | Houston, TX 77057 | Oil & Gas Operator | Dec 1994 |
| 442 | Sapient Energy Corp | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 2002 |
| 443 | Scheriger Production | Graham, TX 76450 | Oil & Gas Operator | Jun 2006 |
| 444 | SCS Newton Oil LLC | Perryton, TX 79070 | Oil & Gas Operator | Apr 2024 |
| 445 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 446 | Service Drilling Co. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 1998 |
| 447 | SGP Operating LLC | Dallas, TX 75205 | Oil & Gas Operator | Apr 2024 |
| 448 | Shell Trading Us Company | Houston, TX 77210 | Oil & Gas Operator | Jan 2024 |
| 449 | Sheridan Energy,Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2000 |
| 450 | Sidwell Oil & Gas, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Sep 2014 |
| 451 | Skinner, Robert V. | Spearman, TX 79081 | Oil & Gas Operator | Aug 2008 |
| 452 | Skinnergy Co. | Spearman, TX 79081 | Oil & Gas Operator | Apr 2024 |
| 453 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2024 |
| 454 | SLT Dakota Operating, Inc. | Yukon, OK 73099 | Oil & Gas Operator | Apr 2024 |
| 455 | Smith & Marrs Inc. | Lubbock, TX 79424 | Oil & Gas Operator | Apr 2021 |
| 456 | Sonat Exploration Company-MCR | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 457 | Southcross Operating LLC | Amarillo, TX 79114 | Oil & Gas Operator | Oct 2005 |
| 458 | Southwest Energy LP | Houston, TX 77002 | Oil & Gas Operator | Sep 2022 |
| 459 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | Apr 2024 |
| 460 | Spoonemore Brothers | Spearman, TX 79081 | Oil & Gas Operator | Nov 2019 |
| 461 | Spring Resources, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2007 |
| 462 | SSC, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | Apr 2024 |
| 463 | St. Johns Operating #1 L.P. | Houston, TX 77060 | Oil & Gas Operator | Aug 2023 |
| 464 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 465 | Stonetown Properties, LTD. | Amarillo, TX 79114 | Oil & Gas Operator | Dec 2016 |
| 466 | Strand Energy, Inc. (I) | Houston, TX 77002 | Oil & Gas Operator | Sep 1996 |
| 467 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 468 | Strat Land Exploration Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2024 |
| 469 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Apr 2024 |
| 470 | Sundown Energy, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Dec 2023 |
| 471 | Sunlight Exploration, Inc. | Canyon, TX 79015 | Oil & Gas Operator | Apr 2024 |
| 472 | Sunstone Energy Company | Tulsa, OK 74153 | Oil & Gas Operator | Aug 2009 |
| 473 | Suoco Oil Corporation | Pampa, TX 79066 | Oil & Gas Operator | Apr 2024 |
| 474 | Sutherland Energy Co., LLC | Bridgeport, TX 76426 | Oil & Gas Operator | Apr 2024 |
| 475 | Swope Corp. | Austin, TX 78735 | Oil & Gas Operator | Apr 2024 |
| 476 | T-Y Development Corp | Perryton, TX 79070 | Oil & Gas Operator | Apr 2024 |
| 477 | Tabula Rasa Energy, LLC | Allen, TX 75013 | Oil & Gas Operator | Dec 2020 |
| 478 | Taos Resources Operating Co LLC | Houston, TX 77037 | Oil & Gas Operator | Dec 2019 |
| 479 | Taylor Energy Corporation | Amarillo, TX 79114 | Oil & Gas Operator | Feb 1999 |
| 480 | TC Oil And Gas, LLC | Denton, TX 76205 | Oil Operator | Apr 2024 |
| 481 | Tecolote Energy Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Jan 2024 |
| 482 | Templar Operating LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Jan 2024 |
| 483 | Tenison Oil Company | Abilene, TX 79605 | Oil & Gas Operator | Apr 2024 |
| 484 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Apr 2024 |
| 485 | Texakoma E & P, LLC | Plano, TX 75024 | Oil & Gas Operator | Apr 2024 |
| 486 | Texas American Resources Company | Austin, TX 78701 | Oil & Gas Operator | Apr 2024 |
| 487 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 488 | Thompson Operating Co. | Abernathy, TX 79311 | Oil & Gas Operator | Aug 1994 |
| 489 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 490 | TK Drilling Corp. | Tulsa, OK 74133 | Oil & Gas Operator | Jan 2024 |
| 491 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 492 | Trail Ridge Energy Partners, LLC | Grapevine, TX 76051 | Oil & Gas Operator | Feb 2024 |
| 493 | Transpetco I | Shreveport, LA 71101 | Oil & Gas Operator | May 2009 |
| 494 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Apr 2024 |
| 495 | Trivestco Energy Company | Ponca City, OK 74601 | Oil & Gas Operator | Feb 2024 |
| 496 | Troup Oil & Gas, LLC | Oklahoma City, OK 73112 | Oil Operator | Apr 2024 |
| 497 | TT Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2024 |
| 498 | Tuthill & Barbee | Amarillo, TX 79101 | Oil & Gas Operator | Nov 1994 |
| 499 | Unbridled Resources, LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 500 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |