| 401 | Southern Resources Inc | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | May 2025 |
| 402 | Southern Star Central Gas Pipeline, Inc. | Owensboro, KY 42301 | Oil & Gas Operator | Apr 2025 |
| 403 | Southwestern Exploration Consultants Inc | Oklahoma City, OK 73118-1116 | Oil & Gas Operator | Apr 2025 |
| 404 | SP Energy Development Company | Seattle, WA 98101-3277 | Oil & Gas Operator | Mar 2015 |
| 405 | Special Energy Corporation | Stillwater, OK 74076 | Oil & Gas Operator | Jul 2025 |
| 406 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | May 2025 |
| 407 | Spring Valley Oil & Gas Inc | Drummond, OK 73735 | Oil & Gas Operator | May 2025 |
| 408 | Squirrel Oil & Gas Inc | Tonkawa, OK 74653 | Oil & Gas Operator | Mar 2022 |
| 409 | Stallion Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2017 |
| 410 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Jul 2025 |
| 411 | Stillwater Oil & Gas | Irving, TX 75062 | Oil & Gas Operator | Mar 2015 |
| 412 | STP Cherokee, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2014 |
| 413 | STP Newco Inc | Oklahoma City, OK 73102-5641 | Oil & Gas Operator | Jul 2021 |
| 414 | Strat Land Exploration Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 415 | Struthers Oil & Gas Corp | Tulsa, OK 74133 | Oil & Gas Operator | Jan 2013 |
| 416 | Summa Engineering Inc | Oklahoma City, OK 73112-3624 | Oil & Gas Operator | Mar 2015 |
| 417 | Sundance Operating Co | | Oil & Gas Operator | Jul 2016 |
| 418 | Superior Oil & Gas LLC | Ringwood, OK 73768-9658 | Oil & Gas Operator | May 2025 |
| 419 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 420 | Supplyco Inc | Perry, OK 73077 | Oil & Gas Operator | Apr 2014 |
| 421 | Swenton, Michael J. | Tulsa, OK 74105 | Oil & Gas Operator | Apr 2025 |
| 422 | T B K Energy Company | Brenham, TX 77833 | Oil & Gas Operator | Apr 2025 |
| 423 | Tag Team Resources LLC | Eufaula, OK 74432 | Oil & Gas Operator | Apr 2025 |
| 424 | Tallgrass Energy, L.L.C. | Tulsa, OK 74136 | Oil & Gas Operator | Jul 2025 |
| 425 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 426 | Tapstone Energy LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | May 2025 |
| 427 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Apr 2025 |
| 428 | Territory Resources LLC | Stillwater, OK 74074-1869 | Oil & Gas Operator | Jun 2025 |
| 429 | Tessera Energy LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Apr 2025 |
| 430 | Texaco Expl. And Prod. Inc. | Houston, TX 77236 | Oil & Gas Operator | May 2025 |
| 431 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 432 | Texas Meridian Operating Co. Inc | Houston, TX 77079 | Oil & Gas Operator | Oct 1993 |
| 433 | Three Forks Resources LLC | Wheat Ridge, CO 80033 | Oil & Gas Operator | Jul 2025 |
| 434 | Three Sands Investment Company | Waukomis, OK 73773 | Oil & Gas Operator | Apr 2025 |
| 435 | Titan Resources LTD | Limaville, OH 44640 | Oil & Gas Operator | May 2025 |
| 436 | Toklan Oil And Gas Corporation | Tulsa, OK 74136 | Oil & Gas Operator | May 2025 |
| 437 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 438 | Totalfinaelf E&P USA Inc | Houston, TX 77024 | Oil & Gas Operator | Jul 2007 |
| 439 | Transamerican Energy LTD | Dallas, TX 75231-1075 | Oil & Gas Operator | Apr 2014 |
| 440 | Transfuel Resources Co | Houston, TX 77215 | Oil & Gas Operator | Aug 2013 |
| 441 | Tri-State Pipeline Service Inc | Ninnekah, OK 73067-0189 | Oil & Gas Operator | Mar 2011 |
| 442 | Triad Energy, Inc. | Oklahoma City, OK 73105-1401 | Oil & Gas Operator | May 2025 |
| 443 | Trigg Drilling Company Inc | Oklahoma City, OK 73105 | Oil & Gas Operator | Jan 2013 |
| 444 | Tulsa Energy Partners LLC | Tulsa, OK 74103-4461 | Oil & Gas Operator | May 2025 |
| 445 | Turner Resources Inc | Hennessey, OK 73742 | Oil & Gas Operator | Apr 2025 |
| 446 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 447 | Txok Energy Resources Company | Tulsa, OK 74172-0140 | Oil & Gas Operator | Feb 2017 |
| 448 | Ultramar Oil & Gas LTD | Houston, TX 77060 | Oil & Gas Operator | Jul 1995 |
| 449 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 450 | Union Valley Petroleum Corporation | Enid, OK 73701 | Oil & Gas Operator | May 2025 |
| 451 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2025 |
| 452 | United Production Company LLC | Edmond, OK 73003 | Oil & Gas Operator | May 2025 |
| 453 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Jul 2025 |
| 454 | Vantage Point Operating Co | Houston, TX 77057 | Oil & Gas Operator | Dec 2014 |
| 455 | Veenker Resources, Inc. | Oklahoma City, OK 73113 | Oil & Gas Operator | May 2025 |
| 456 | Victory Oil & Gas Inc | Gun Barrel Cy, TX 75156 | Oil & Gas Operator | Jul 2025 |
| 457 | Viersen & Cochran Drilling Company | | Oil & Gas Operator | May 2015 |
| 458 | Vitruvian Exploration LLC | The Woodlands, TX 77380 | Oil & Gas Operator | May 2016 |
| 459 | W M A Corporation | Wichita, KS 67278-1713 | Oil & Gas Operator | Jan 1998 |
| 460 | Wabash Energy Corporation | Lawrenceville, IL 62439 | Oil & Gas Operator | Dec 2009 |
| 461 | Wadkins T Roy | Bartlesville, OK 74006 | Oil & Gas Operator | Nov 2019 |
| 462 | Wellco Energy Inc | Harrah, OK 73045 | Oil & Gas Operator | Apr 2025 |
| 463 | Wessely Energy Company | Dallas, TX 75206 | Oil & Gas Operator | May 2001 |
| 464 | Wheeler Energy Co. | Tulsa, OK 74101 | Oil & Gas Operator | Apr 2025 |
| 465 | Whitaker Energy Inc | Humble, TX 77346-1798 | Oil & Gas Operator | May 2025 |
| 466 | White Goat Resources LLC | Yukon, OK 73099 | Oil & Gas Operator | May 2025 |
| 467 | White Star Petroleum LLC | Oklahoma City, OK 73116-7906 | Oil & Gas Operator | Feb 2025 |
| 468 | Whiteman Industries, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Jun 2024 |
| 469 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 470 | Whitmar Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Apr 2025 |
| 471 | Wil-MC Oil Corporation The | Irving, TX 75015-2510 | Oil & Gas Operator | Mar 1999 |
| 472 | Wildhorse Oil & Gas Corporation | Ardmore, OK 73402 | Oil & Gas Operator | May 2019 |
| 473 | Wildhorse Operating Company | Ardmore, OK 73402 | Oil & Gas Operator | Jul 2025 |
| 474 | Wishbone Oil & Gas | Noble, OK 73068 | Oil & Gas Operator | Mar 2007 |
| 475 | Wood Fay C Estate | Enid, OK 73703 | Oil & Gas Operator | Jun 2013 |
| 476 | Woolsey Petroleum Corporation | Wichita, KS 67202 | Oil & Gas Operator | Mar 2025 |
| 477 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 478 | Yale Oil Association, Inc. | Oklahoma City, OK 73105 | Oil & Gas Operator | May 2025 |
| 479 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | May 2025 |