| 501 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 502 | Sogc, Inc. | Salt Lake Cty, UT 84131 | Oil & Gas Operator | Feb 2025 |
| 503 | Sorrels J R Dba Cheyenne Oil Properties | Ponca City, OK 74601 | Oil & Gas Operator | Jul 2022 |
| 504 | Southern Resources Inc | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | Jan 2025 |
| 505 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 506 | Southwest Energy LP | Houston, TX 77002 | Oil & Gas Operator | Jan 2025 |
| 507 | Spartan Resources LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2025 |
| 508 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | Feb 2025 |
| 509 | Spring Resources, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2007 |
| 510 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 511 | Staab Alan R | Tulsa, OK 74114-4213 | Oil & Gas Operator | Sep 2010 |
| 512 | Stalwart Energy Co | Tulsa, OK 74103-3518 | Oil & Gas Operator | Apr 2014 |
| 513 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2025 |
| 514 | Stover Company | Tulsa, OK 74152-0786 | Oil & Gas Operator | Jan 2013 |
| 515 | Strike Energy LLC | Burneyville, OK 73430 | Oil Operator | Jan 2025 |
| 516 | Struthers Oil & Gas Corp | Tulsa, OK 74133 | Oil & Gas Operator | Jan 2013 |
| 517 | Summit Energy, Inc. | Littleton, CO 80127 | Oil & Gas Operator | Aug 2013 |
| 518 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Apr 2025 |
| 519 | Sunoco Partners MKT & Terminal | Tulsa, OK 74102-2039 | Oil & Gas Operator | Jan 2019 |
| 520 | Sunterra Energy Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2009 |
| 521 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 522 | SWN Production LLC | Spring, TX 77389-4954 | Oil & Gas Operator | Feb 2022 |
| 523 | Sydson D'Oro Expl. Co. | Houston, TX 77079 | Oil & Gas Operator | Jan 1992 |
| 524 | T C Craighead & Company LLC | Ardmore, OK 73401 | Oil & Gas Operator | Aug 2019 |
| 525 | Tag Team Resources LLC | Eufaula, OK 74432 | Oil & Gas Operator | Jan 2025 |
| 526 | Tau Ventures | Tulsa, OK 74105-1026 | Oil & Gas Operator | Jan 2025 |
| 527 | Taylor R C Companies Inc | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | May 2021 |
| 528 | Tenaska Marketing Ventures | Omaha, NE 68154 | Oil & Gas Operator | Mar 2021 |
| 529 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Dec 2024 |
| 530 | Texaco Expl. And Prod. Inc. | Houston, TX 77236 | Oil & Gas Operator | Dec 2024 |
| 531 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 532 | Texas Meridian Operating Co. Inc | Houston, TX 77079 | Oil & Gas Operator | Oct 1993 |
| 533 | Texinia Corp | Dallas, TX 75201 | Oil & Gas Operator | Jun 2015 |
| 534 | Texinia Limited Partnership | Dallas, TX 75201 | Gas Operator | Jan 2017 |
| 535 | Texinia Oil & Gas Inc. | Dallas, TX 75214 | Oil & Gas Operator | Jan 2025 |
| 536 | Texland Petroleum Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2003 |
| 537 | The Twenty Eleven Corp Inc | Ada, OK 74820-3605 | Oil Operator | Jan 2025 |
| 538 | Thomas J L Engineering Inc | Edmond, OK 73003-0026 | Oil & Gas Operator | Jul 2016 |
| 539 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 540 | Tidemark Exploration | Tulsa, OK 74170 | Oil & Gas Operator | May 2005 |
| 541 | Tiger Trucks Inc | Seminole, OK 74868 | Oil & Gas Operator | Feb 2025 |
| 542 | Tilford Pinson Exploration LLC | Edmond, OK 73003 | Oil & Gas Operator | Jan 2025 |
| 543 | TK Drilling Corp. | Tulsa, OK 74133 | Oil & Gas Operator | Jan 2025 |
| 544 | Totalfinaelf E&P USA Inc | Houston, TX 77024 | Oil & Gas Operator | Jul 2007 |
| 545 | Trafalgar House Oil & Gas Inc. | Houston, TX 77002-7346 | Oil & Gas Operator | Jan 1992 |
| 546 | Transfuel Resources Co | Houston, TX 77215 | Oil & Gas Operator | Aug 2013 |
| 547 | Transok LLC | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Jul 2020 |
| 548 | Travis Peak Resources LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 549 | Trepco Production Company, Inc. | Yukon, OK 73099 | Oil & Gas Operator | Jan 2025 |
| 550 | Trepel Petroleum Exploration & | | Oil & Gas Operator | Apr 2014 |
| 551 | Triad Energy, Inc. | Oklahoma City, OK 73105-1401 | Oil & Gas Operator | Feb 2025 |
| 552 | Tridon Oil Inc | Lafayette, LA 70505-2305 | Gas Operator | Dec 2013 |
| 553 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 554 | Tripower Resources LLC | Ardmore, OK 73402 | Oil & Gas Operator | Apr 2025 |
| 555 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 556 | Trout Disposal Well Inc | Hammon, OK 73650 | Oil & Gas Operator | Jul 2016 |
| 557 | Troy Energy Operating LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2025 |
| 558 | TRP-Ok Properties LLC | Norman, OK 73072 | Oil & Gas Operator | Feb 2025 |
| 559 | Truckers Disposal Inc | Skiatook, OK 74070 | Oil & Gas Operator | Jan 2025 |
| 560 | Truevine Gas Company | Ada, OK 74821-1422 | Oil & Gas Operator | Jan 2025 |
| 561 | Tucker Ron & Co | Norman, OK 73069-8511 | Gas Operator | Sep 2017 |
| 562 | Turntable Energy Inc | Ponca City, OK 74604 | Oil & Gas Operator | Jan 2025 |
| 563 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 564 | Txok Energy Resources Company | Tulsa, OK 74172-0140 | Oil & Gas Operator | Feb 2017 |
| 565 | Tytan Operating Company LLC | Edmond, OK 73083-3794 | Oil & Gas Operator | May 2016 |
| 566 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 567 | Unicon Producing Company | Houston, TX 75252 | Gas Operator | Mar 1994 |
| 568 | Union Texas Petroleum Corp. | Houston, TX 77252-2120 | Oil & Gas Operator | Dec 2014 |
| 569 | Unit Drilling & Exploration Co | Tulsa, OK 74132-5300 | Oil & Gas Operator | Jan 2025 |
| 570 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2025 |
| 571 | United Energy Operating, LLC | Edmond, OK 73083 | Oil & Gas Operator | Apr 2025 |
| 572 | United Energy Trading LLC | Tulsa, OK 74133 | Oil & Gas Operator | Jan 2025 |
| 573 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Apr 2025 |
| 574 | Vanguard Permian LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 575 | Vantage Point Operating Co | Houston, TX 77057 | Oil & Gas Operator | Dec 2014 |
| 576 | Vastar Resources Inc | Houston, TX 77253 | Oil & Gas Operator | Dec 2024 |
| 577 | Vectra CBM LLC | Littleton, CO 80128-4557 | Gas Operator | Jan 2014 |
| 578 | Vega Energy Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Sep 2015 |
| 579 | Ventana Exploration And Production II LLC | Oklahoma City, OK 73134-2519 | Oil & Gas Operator | Jan 2025 |
| 580 | Vintage Gas Inc | Tulsa, OK 74119-1029 | Oil & Gas Operator | Jun 2007 |
| 581 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Jan 2025 |
| 582 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 583 | Ward Gas Marketing Inc | Enid, OK 73702 | Oil & Gas Operator | Sep 2011 |
| 584 | Ward Oil Company An Okla Corp | McAlester, OK 74501 | Oil & Gas Operator | Feb 1993 |
| 585 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Jan 2025 |
| 586 | Waterbridge Arkoma Operating LLC | Houston, TX 77056 | Oil Operator | Feb 2025 |
| 587 | Weatherly Nell M Estate | Ada, OK 74821-0669 | Oil & Gas Operator | Feb 1997 |
| 588 | Wentworth Operating Company | Oklahoma City, OK 73162-1863 | Oil & Gas Operator | Feb 2025 |
| 589 | WFD Oil Corporation | Edmond, OK 73012-0619 | Oil & Gas Operator | Jan 2025 |
| 590 | Wheeler Energy Co. | Tulsa, OK 74101 | Oil & Gas Operator | Jan 2025 |
| 591 | Wheeler Energy, LLC | Tulsa, OK 74101 | Oil & Gas Operator | Apr 2025 |
| 592 | White Wolf Energy LLC | Richardson, TX 75080-5509 | Oil & Gas Operator | Oct 2022 |
| 593 | Whitecap Energy L.L.C. | | Oil & Gas Operator | Sep 2018 |
| 594 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 595 | Whitmar Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Jan 2025 |
| 596 | Whitmar Natural Resources Co | Tulsa, OK 74136-9998 | Oil & Gas Operator | Jun 2004 |
| 597 | Whitmar Operating Company | Tulsa, OK 74103-3515 | Oil & Gas Operator | Apr 2009 |
| 598 | Wilcox Pipe & Supply Co | Oklahoma City, OK 73189 | Oil & Gas Operator | May 2006 |
| 599 | Wild Outdoors Oil LLC | Duncan, OK 73533 | Oil & Gas Operator | Feb 2025 |
| 600 | Williams Reid Oil Co | Dallas, TX 75234 | Oil & Gas Operator | Jan 2025 |