| 401 | Settlers Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Nov 2000 |
| 402 | Shamrock Well Operations LLC | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | Dec 2025 |
| 403 | Sharber Billy Jack Operating | Konawa, OK 74849-0071 | Oil & Gas Operator | Mar 2015 |
| 404 | Shawver & Son Inc | Oklahoma City, OK 73154-0778 | Oil & Gas Operator | Oct 2024 |
| 405 | Shields Energy Inc | Fort Smith, AR 72901-4607 | Oil & Gas Operator | Nov 2025 |
| 406 | Shields Operating Inc | Fort Smith, AR 72901-3834 | Oil & Gas Operator | Oct 2021 |
| 407 | Signature Exploration Inc. | Shawnee, OK 74804-4130 | Oil & Gas Operator | Mar 2015 |
| 408 | Silver Creek Oil & Gas, LLC | Flower Mound, TX 75022 | Oil & Gas Operator | Feb 2026 |
| 409 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Nov 2025 |
| 410 | Singer-Fleischaker Oil Op Co | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2002 |
| 411 | Sju Holdings LLC | Norman, OK 73072 | Oil & Gas Operator | Nov 2025 |
| 412 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 413 | SNR Central Oklahoma Operating LLC | Oklahoma City, OK 73116-7906 | Oil Operator | Dec 2025 |
| 414 | SNR Operating, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Feb 2026 |
| 415 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 416 | Sooner Drilling Inc | Shawnee, OK 74802-0037 | Oil & Gas Operator | Jan 2005 |
| 417 | Southcreek Petroleum Co LLC | Blanchard, OK 73010-4911 | Oil & Gas Operator | Oct 2025 |
| 418 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |
| 419 | Southern Resources Inc | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | Dec 2025 |
| 420 | Southwest Exploration Company | Oklahoma City, OK 73132-2230 | Oil & Gas Operator | Jun 2017 |
| 421 | SP Energy Development Company | Seattle, WA 98101-3277 | Oil & Gas Operator | Mar 2015 |
| 422 | Sparks Resources Inc | Bristow, OK 74010 | Oil & Gas Operator | Dec 2025 |
| 423 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | Dec 2025 |
| 424 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 425 | Stark Oil Properties | Asher, OK 74826 | Oil & Gas Operator | Jan 1997 |
| 426 | Statex Petroleum Inc | Dallas, TX 75229 | Oil & Gas Operator | Dec 2000 |
| 427 | Stauros Operating Company | Edmond, OK 73083-2707 | Oil & Gas Operator | Mar 2001 |
| 428 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 429 | Stetson Energy Corporation | Duncan, OK 73534-0098 | Oil & Gas Operator | Mar 2015 |
| 430 | Strat Land Exploration Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2025 |
| 431 | Streamline Oil And Gas Inc | Lindsay, OK 73052 | Oil & Gas Operator | Dec 2025 |
| 432 | Sullivant G W | Oklahoma City, OK 73172-1135 | Oil & Gas Operator | Aug 2001 |
| 433 | Sunterra Energy Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2009 |
| 434 | Swadley Et Al | Holdenville, OK 74848-0794 | Oil & Gas Operator | Nov 2014 |
| 435 | Sweetwater Exploration LLC | Norman, OK 73069-5636 | Oil & Gas Operator | Nov 2025 |
| 436 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 437 | SWN Production LLC | Spring, TX 77389-4954 | Oil & Gas Operator | Feb 2022 |
| 438 | T C Craighead & Company LLC | Ardmore, OK 73401 | Oil & Gas Operator | Aug 2019 |
| 439 | Tat, Inc. | Oklahoma City, OK 73127 | Oil & Gas Operator | Feb 2023 |
| 440 | Taylor R C Companies Inc | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | May 2021 |
| 441 | Te-Ray Resources, LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Feb 2026 |
| 442 | Tema Oil Company | Amarillo, TX 79101 | Oil & Gas Operator | Jun 2009 |
| 443 | Terra Production Company | Okemah, OK 74859-5924 | Oil & Gas Operator | Apr 2020 |
| 444 | Texas American Oil Corporation | Midland, TX 79701 | Oil & Gas Operator | Jan 2001 |
| 445 | The Quintin Little Company Inc | Ardmore, OK 73401 | Oil & Gas Operator | Dec 2025 |
| 446 | Thomas J L Engineering Inc | Edmond, OK 73003-0026 | Oil & Gas Operator | Jul 2016 |
| 447 | Thomas, R. W. Inc. | Norman, OK 73070 | Oil & Gas Operator | Apr 2015 |
| 448 | Tidemark Exploration | Tulsa, OK 74170 | Oil & Gas Operator | May 2005 |
| 449 | Toklan Oil And Gas Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Dec 2025 |
| 450 | Toklan Oil Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 451 | Trail Ridge Energy Partners, LLC | Grapevine, TX 76051 | Oil & Gas Operator | Dec 2025 |
| 452 | Transoil, Inc. | Oklahoma City, OK 73129 | Oil & Gas Operator | Feb 2026 |
| 453 | Trey Resources Inc. | Midland, TX 79710 | Oil & Gas Operator | Nov 2025 |
| 454 | Trigg Drilling Company Inc | Oklahoma City, OK 73105 | Oil & Gas Operator | Jan 2013 |
| 455 | Trilogy Natural Resources LLC | Edmond, OK 73025 | Oil Operator | Nov 2025 |
| 456 | Trinity Resources, Inc. | Houston, TX 77277 | Oil & Gas Operator | May 2020 |
| 457 | Tripower Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2020 |
| 458 | TRP-Ok Properties LLC | Norman, OK 73072 | Oil & Gas Operator | Dec 2025 |
| 459 | Twenty/Twenty Oil & Gas Inc | Hennessey, OK 73742 | Oil & Gas Operator | Dec 2025 |
| 460 | Twisted Resources Inc | Blanchard, OK 73010-8463 | Oil & Gas Operator | Dec 2025 |
| 461 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 462 | Ultramar Oil & Gas LTD | Houston, TX 77060 | Oil & Gas Operator | Jul 1995 |
| 463 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 464 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 465 | Union Texas Petroleum Corp | Houston, TX 77252-2120 | Oil & Gas Operator | Dec 2014 |
| 466 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2026 |
| 467 | United Oil Corporation | Denver, CO 80202-3813 | Oil & Gas Operator | Nov 2025 |
| 468 | United Production Company LLC | Edmond, OK 73003 | Oil & Gas Operator | Dec 2025 |
| 469 | Vaughan Otto M | | Oil & Gas Operator | Apr 2014 |
| 470 | Veenker Resources Inc | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2025 |
| 471 | Vega Energy Company | Nichols Hill, OK 73116 | Oil & Gas Operator | Sep 2015 |
| 472 | Viersen & Cochran Drilling Company | | Oil & Gas Operator | May 2015 |
| 473 | Vitol Inc. | Houston, TX 77098 | Oil & Gas Operator | Sep 2023 |
| 474 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Nov 2025 |
| 475 | Weaver Energy Corporation | Hennessey, OK 73742-1232 | Oil & Gas Operator | Dec 2025 |
| 476 | Wentworth Operating Company | Oklahoma City, OK 73162-1863 | Oil & Gas Operator | Dec 2025 |
| 477 | Western Oil And Gas Development Corp | Oklahoma City, OK 73103-3735 | Oil & Gas Operator | Dec 2025 |
| 478 | Western Oil Company | Midland, TX 79702 | Oil & Gas Operator | Jul 2014 |
| 479 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 480 | Wil-MC Oil Corporation The | Irving, TX 75015-2510 | Oil & Gas Operator | Mar 1999 |
| 481 | Wilcox Pipe & Supply Co | Oklahoma City, OK 73189 | Oil & Gas Operator | May 2006 |
| 482 | Williams Dale And Dorothy Family Trust | Maud, OK 74854-2011 | Oil & Gas Operator | Nov 2025 |
| 483 | Wilshire Enterprises Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 484 | WLW Oil & Gas LLC | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2025 |
| 485 | Xanadu Exploration Company | Broken Arrow, OK 74014 | Oil & Gas Operator | Dec 2025 |
| 486 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Feb 2026 |
| 487 | Y D F Inc | Oklahoma City, OK 73128 | Oil & Gas Operator | Jan 2026 |
| 488 | Yale Oil Association, Inc. | Oklahoma City, OK 73105 | Oil & Gas Operator | Dec 2025 |
| 489 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | Dec 2025 |