| 501 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 502 | SDG Operating Company, Inc | Tyler, TX 75701 | Oil & Gas Operator | Jul 2025 |
| 503 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 504 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 505 | Shappell Oil Company, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Jul 2025 |
| 506 | Shelby Operating Company | Dallas, TX 75205 | Oil & Gas Operator | Jul 2025 |
| 507 | Shelby, Michael H. | Shreveport, LA 71101 | Oil & Gas Operator | Jul 2025 |
| 508 | Sheridan Production Co III, LLC | Houston, TX 77056 | Oil & Gas Operator | Jul 2025 |
| 509 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Apr 2025 |
| 510 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Jul 2025 |
| 511 | Shivers, Linward, Operator | Shreveport, LA 71161 | Oil & Gas Operator | Sep 1997 |
| 512 | Shoco Production, L.P. | Kilgore, TX 75663 | Oil & Gas Operator | May 2020 |
| 513 | Shoshone Oil Company | Dallas, TX 75244 | Oil & Gas Operator | May 1994 |
| 514 | SHWJ Oil & Gas Co., Inc. | Oil City, LA 71061 | Oil Operator | Jul 2025 |
| 515 | Sikes Operating, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Jun 2003 |
| 516 | Silver Creek Oil & Gas, LLC | Flower Mound, TX 75022 | Oil & Gas Operator | Jul 2025 |
| 517 | Silver Hill Energy Operating, LLC | Dallas, TX 75201 | Oil & Gas Operator | Jul 2025 |
| 518 | Silver Oak Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Dec 2009 |
| 519 | Silver Oak Operating, LLC | Longview, TX 75604 | Oil & Gas Operator | Jul 2025 |
| 520 | Sinclair Development, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Jul 2025 |
| 521 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Jul 2025 |
| 522 | Slant Operating, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Jul 2025 |
| 523 | SM Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Jul 2025 |
| 524 | Smal Energy Corp | Tyler, TX 75710 | Oil & Gas Operator | Oct 1995 |
| 525 | Smith Operating & Management Co. | Shreveport, LA 71161 | Oil & Gas Operator | Feb 2005 |
| 526 | Smith Operating And MGMT Co. | Shreveport, LA 71161 | Oil & Gas Operator | Jun 2023 |
| 527 | Smith Resources, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Jul 2025 |
| 528 | Smith Resources, L.L.C. | Marshall, TX 75671 | Oil & Gas Operator | Jul 2025 |
| 529 | Smith, E.N. III Energy Corp. | Marshall, TX 75671 | Oil & Gas Operator | Sep 2006 |
| 530 | Snyder Partners | Cody, WY 82414 | Oil & Gas Operator | May 2025 |
| 531 | Sogc, Inc. | Salt Lake Cty, UT 84131 | Oil & Gas Operator | May 2025 |
| 532 | Sojitz Energy Venture, Inc. | Houston, TX 77042 | Oil & Gas Operator | Feb 2018 |
| 533 | Soldier Creek Energy, LLC | Edmond, OK 73013 | Oil & Gas Operator | Jul 2025 |
| 534 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 535 | Sonat Exploration Company -Tyler | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 536 | Sonat Exploration Company-MCR | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 537 | Sonora Petroleum Corp. | Austin, TX 78734 | Oil & Gas Operator | Jul 2025 |
| 538 | Southerland, Glenn Oil & Gas Co. | Hallsville, TX 75650 | Oil & Gas Operator | Feb 2021 |
| 539 | Southern Crude, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2017 |
| 540 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | Jul 2025 |
| 541 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 542 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | Jul 2025 |
| 543 | Sponte Operating, Inc. | Dallas, TX 75313 | Oil & Gas Operator | Jul 2025 |
| 544 | Stroud Petroleum, Inc. | Shreveport, LA 71162 | Oil & Gas Operator | Jul 2025 |
| 545 | Stuart Oil & Gas | Longview, TX 75606 | Oil & Gas Operator | Jul 2025 |
| 546 | Sunland Production Company, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jun 2025 |
| 547 | Superior Royalty, LLC | Lindale, TX 75771 | Oil Operator | Jul 2025 |
| 548 | SW Operating, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Sep 2000 |
| 549 | Sydri Operating, LLC | Dallas, TX 75231 | Oil & Gas Operator | Jul 2025 |
| 550 | T W Clemons Operating Co., LLC | Minden, LA 71055 | Oil & Gas Operator | Jul 2025 |
| 551 | T. And M. Production | Oil City, LA 71061 | Oil & Gas Operator | Jul 2025 |
| 552 | T.O.I. | Midland, TX 79710 | Oil & Gas Operator | Mar 2001 |
| 553 | Tanos Exploration II, LLC | Tyler, TX 75701 | Oil & Gas Operator | Sep 2023 |
| 554 | Tanos Exploration IV, LLC | Tyler, TX 75703 | Oil & Gas Operator | Jul 2025 |
| 555 | Tanos Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Oct 2018 |
| 556 | TC Energy LLC | Covington, OK 73730-2116 | Oil & Gas Operator | Sep 2014 |
| 557 | TC Oil And Gas, LLC | Denton, TX 76205 | Oil Operator | Jul 2025 |
| 558 | TC3 Energy Company | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 559 | Tenison Oil Company | Abilene, TX 79605 | Oil & Gas Operator | Jul 2025 |
| 560 | Terry Petroleum Company | Houston, TX 77270 | Oil & Gas Operator | Dec 1997 |
| 561 | Tesoro E&P Company, L.P. | San Antonio, TX 78216 | Oil & Gas Operator | Jan 2000 |
| 562 | Tex-Ok Energy, LTD Partnership | Cody, WY 82414 | Oil & Gas Operator | Jul 2025 |
| 563 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Jul 2025 |
| 564 | Texas Royalty Corp. | Austin, TX 78746 | Oil & Gas Operator | Jul 2025 |
| 565 | Texla Operating Co | Jonesville, TX 75659 | Oil & Gas Operator | Jul 2025 |
| 566 | Texlan Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Nov 1994 |
| 567 | Texlan Oil Company, L.C. | Tyler, TX 75711 | Oil & Gas Operator | Aug 2003 |
| 568 | TGNR East Texas II LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 569 | TGNR East Texas LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 570 | TGNR Gulf Coast LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 571 | TGNR TVL LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 572 | The Termo Company | Long Beach, CA 90801 | Oil & Gas Operator | May 2025 |
| 573 | Thor-Max Operating, Inc. | Plano, TX 75025 | Oil & Gas Operator | Jul 2025 |
| 574 | Thunder Oil & Gas, LLC | Ardmore, OK 73402 | Oil & Gas Operator | Apr 2025 |
| 575 | Thunderbird (Texas) Resources LP | Edmond, OK 73025 | Oil & Gas Operator | Apr 2019 |
| 576 | Tipco Operating Co. | Marshall, TX 75671 | Oil & Gas Operator | Jul 2025 |
| 577 | Titan Rock E&P, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Jan 2024 |
| 578 | Torch Energy Services, Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2011 |
| 579 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 580 | Trans-Texas Resources, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 1993 |
| 581 | Tri-State Exploration & Prod Inc | Marshall, TX 75671 | Oil & Gas Operator | Aug 2003 |
| 582 | Trich Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2025 |
| 583 | Trico Oil & Gas Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Jul 2025 |
| 584 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 585 | Triple J Investments Inc | Longview, TX 75606 | Oil & Gas Operator | Feb 2023 |
| 586 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 587 | Trivium Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Jul 2025 |
| 588 | Tyler Oil & Gas Inc. | Tyler, TX 75702 | Oil & Gas Operator | Sep 2004 |
| 589 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 590 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2025 |
| 591 | Uptex Operating Inc. | Dallas, TX 75201 | Oil & Gas Operator | May 2011 |
| 592 | Uptex Operating, L.P. | Dallas, TX 75201 | Oil & Gas Operator | May 2010 |
| 593 | Ursus Oil And Gas | Tyler, TX 75703 | Oil & Gas Operator | Jul 2025 |
| 594 | Us. Fuels, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2025 |
| 595 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2025 |
| 596 | Vaughan Operating Company, LLC | Shreveport, LA 71101 | Oil & Gas Operator | Jun 2009 |
| 597 | Vector Energy Corporation | Houston, TX 77060 | Oil & Gas Operator | Jul 2025 |
| 598 | Vector Exploration Inc | Oklahoma City, OK 73142-4430 | Oil & Gas Operator | Dec 2018 |
| 599 | Verado Energy, Inc. | Allen, TX 75013 | Oil & Gas Operator | Jul 2025 |
| 600 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Jul 2025 |