| 601 | Transtexas Gas Corporation | Houston, TX 77265 | Oil & Gas Operator | Aug 2005 |
| 602 | Trap Rock Oil Company | Cambridge, MA 02138 | Oil & Gas Operator | Nov 2005 |
| 603 | Trap Rock Oil, LTD. | Houston, TX 77005 | Oil & Gas Operator | Apr 2026 |
| 604 | Traton Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Mar 2019 |
| 605 | Travelers Oil Company | Amarillo, TX 79102 | Oil & Gas Operator | Apr 2026 |
| 606 | Travers Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Apr 2026 |
| 607 | Travis | Houston, TX 77057 | Oil Operator | Apr 2026 |
| 608 | Travis Operating, LLC | Kingwood, TX 77345 | Oil & Gas Operator | Apr 2026 |
| 609 | Travis, J. J., Trustee | Rockport, TX 78382 | Oil & Gas Operator | Dec 1996 |
| 610 | Treadaway Oil Co. | Balmorhea, TX 79718 | Oil & Gas Operator | Apr 2026 |
| 611 | Treadstone Energy Partners, LLC | Houston, TX 77070 | Oil & Gas Operator | Jun 2016 |
| 612 | Treadstone Energy PRTNR Op, LLC | Katy, TX 77494 | Oil & Gas Operator | Apr 2026 |
| 613 | Treco Oil Company | Albany, TX 76430 | Oil & Gas Operator | Apr 2026 |
| 614 | Tree Operating, LLC | Graham, TX 76450 | Oil & Gas Operator | Apr 2026 |
| 615 | Trejim Operators, LLC | Pampa, TX 79065 | Oil & Gas Operator | Apr 2026 |
| 616 | Trek Aec, LLC | Wichita, KS 67202 | Oil & Gas Operator | Dec 2025 |
| 617 | Trek Exploration, Inc. | Pampa, TX 79065 | Oil & Gas Operator | Apr 2026 |
| 618 | Trek Oil & Gas, Inc | Houston, TX 77002 | Oil Operator | Mar 1998 |
| 619 | Trek Petroleum Company, Inc. | Midland, TX 79707 | Oil & Gas Operator | Apr 2026 |
| 620 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Apr 2026 |
| 621 | Tren Energy LLC | El Paso, TX 79912 | Oil & Gas Operator | Apr 2026 |
| 622 | Trend Exploration Company | Midland, TX 79701 | Oil & Gas Operator | Mar 2008 |
| 623 | Trend Exploration I LLC | Midland, TX 79701 | Oil & Gas Operator | May 2011 |
| 624 | Trenna Oil Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2013 |
| 625 | Tres Azores Oil & Gas, Inc. | Fort Worth, TX 76185 | Oil & Gas Operator | Aug 2003 |
| 626 | Tres Operating Co., LLC | Katy, TX 77494 | Oil Operator | Apr 2026 |
| 627 | Tres Piedras, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Apr 1999 |
| 628 | Tres Roughneckas WTX LLC | MC Camey, TX 79752 | Oil Operator | Apr 2026 |
| 629 | Tresami, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Apr 2026 |
| 630 | Trestle Creek Properties, LLC | Manchaca, TX 78652 | Oil & Gas Operator | Apr 2026 |
| 631 | Trey Exploration, Inc. | San Angelo, TX 76901 | Oil & Gas Operator | Dec 2019 |
| 632 | Trey Operating Company | MC Camey, TX 79752 | Oil Operator | Jan 2016 |
| 633 | Trey Resources Inc. | Midland, TX 79710 | Oil & Gas Operator | Jan 2026 |
| 634 | Trey Services, Inc. | Midland, TX 79711 | Oil & Gas Operator | Dec 1996 |
| 635 | Tri "M" Oil & Gas | Muenster, TX 76252 | Oil & Gas Operator | Apr 2026 |
| 636 | Tri City Oil Co., LLC | Winnie, TX 77665 | Oil Operator | Apr 2026 |
| 637 | Tri Energy Resources, Inc. | Norman, OK 73070 | Oil Operator | Apr 2026 |
| 638 | Tri Sportsmen Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Apr 2026 |
| 639 | Tri Star Operating, Inc. | Arlington, TX 76012 | Oil & Gas Operator | Jan 2002 |
| 640 | Tri-Am Operating Company | Frankston, TX 75763 | Oil & Gas Operator | Apr 2026 |
| 641 | Tri-C Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Aug 2009 |
| 642 | Tri-C Resources, LLC | Houston, TX 77024 | Oil & Gas Operator | Apr 2026 |
| 643 | Tri-Dyne Resources, Inc. | Southern Pine, NC 28387 | Oil & Gas Operator | Feb 2000 |
| 644 | Tri-Ex Petroleum, L.P. | Amarillo, TX 79101 | Oil & Gas Operator | Jan 2013 |
| 645 | Tri-Force Operating, L.L.C. | Royse City, TX 75189 | Oil & Gas Operator | Apr 2026 |
| 646 | Tri-K Production Company, Inc. | Olney, TX 76374 | Oil & Gas Operator | Apr 1996 |
| 647 | Tri-State Exploration & Prod Inc | Marshall, TX 75671 | Oil & Gas Operator | Aug 2003 |
| 648 | Tri-State Resources, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2012 |
| 649 | Tri-State Sales & Production | Rodessa, LA 71069 | Oil & Gas Operator | Dec 2008 |
| 650 | Tri-Tex Exploration LTD | Abilene, TX 79608 | Oil Operator | Apr 2019 |
| 651 | Tri-Union Development Corp. | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 652 | Tri-W Oil | Luling, TX 78648 | Oil Operator | Apr 2026 |
| 653 | Tri-W Oil, Inc. | Luling, TX 78648 | Oil Operator | Apr 2007 |
| 654 | Triad Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Oct 2011 |
| 655 | Triad O&G, LLC | Dallas, TX 75225 | Oil & Gas Operator | Apr 2026 |
| 656 | Triag Energy Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2014 |
| 657 | Triangle Development Co | Mahtomedi, MN 55115 | Gas Operator | Feb 1982 |
| 658 | Triangle Energy Co. | Pampa, TX 79066 | Oil & Gas Operator | Nov 2000 |
| 659 | Triangle P Development Corp. | Bronte, TX 76933 | Oil & Gas Operator | Apr 2026 |
| 660 | Triangle Three Resources L.L.C. | Dallas, TX 75240 | Oil & Gas Operator | Oct 2024 |
| 661 | Triax Energy LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2018 |
| 662 | Trich Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2025 |
| 663 | Trico Energy LLC | Hager Hill, KY 41222 | Oil Operator | Dec 2018 |
| 664 | Trico Oil & Gas Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Apr 2026 |
| 665 | Trident Corporation | Woodsboro, TX 78393 | Oil & Gas Operator | Apr 2026 |
| 666 | Triesco, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 1996 |
| 667 | Triforce Energy LLC | Littleton, CO 80122 | Oil & Gas Operator | Apr 2026 |
| 668 | Trigeo Energy, LLC | Addison, TX 75001 | Oil & Gas Operator | Apr 2026 |
| 669 | Trigo Oil And Gas, LLC | Amarillo, TX 79101 | Oil & Gas Operator | Mar 2022 |
| 670 | Trilogy Operating, Inc. | Midland, TX 79708 | Oil & Gas Operator | Apr 2026 |
| 671 | Trinidad Energy, LLC | Midland, TX 79708 | Oil & Gas Operator | Apr 2026 |
| 672 | Trinidad Exploration, Inc. | Tyler, TX 75703 | Oil & Gas Operator | Mar 2008 |
| 673 | Trinidad Petroleum, Inc. | Austin, TX 78711 | Oil & Gas Operator | Apr 2026 |
| 674 | Trinidad Resources, LLC | San Antonio, TX 78217 | Oil & Gas Operator | Apr 2026 |
| 675 | Trinity Bay Oil & Gas, Inc. | Lubbock, TX 79416 | Oil & Gas Operator | Apr 2026 |
| 676 | Trinity Eor, LLC | Midland, TX 79701 | Oil & Gas Operator | Jan 2019 |
| 677 | Trinity Gas Corporation | Edmond, OK 73003 | Oil & Gas Operator | Apr 2026 |
| 678 | Trinity Gas Storage, LLC | Flower Mound, TX 75028 | Oil & Gas Operator | Apr 2026 |
| 679 | Trinity Minerals&Operating Corp. | Abilene, TX 79605 | Oil & Gas Operator | Dec 1995 |
| 680 | Trinity Operating & Prod., Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 681 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 682 | Trinity Resources, Inc. | Houston, TX 77277 | Oil & Gas Operator | May 2020 |
| 683 | Trinity River Energy Oper, LLC | Houston, TX 77008 | Oil & Gas Operator | May 2018 |
| 684 | Trinity River Operating Company | Oklahoma City, OK 73147 | Oil & Gas Operator | Apr 2026 |
| 685 | Trio Consulting & Management,LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2026 |
| 686 | Trio Operating Company, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2006 |
| 687 | Trio Production Company, LLC | Stephens, AR 71764 | Oil Operator | Jan 2025 |
| 688 | Triple "B" Production DRLG Inc | Poynor, TX 75782 | Oil & Gas Operator | Sep 2022 |
| 689 | Triple "G" Oil Company | Clyde, TX 79510 | Oil & Gas Operator | Apr 1999 |
| 690 | Triple "N" Services, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2026 |
| 691 | Triple "S" Gas, Inc. | Louisville, KY 40255 | Oil & Gas Operator | Jan 2026 |
| 692 | Triple "S" Resources Inc | Sapulpa, OK 74066 | Oil & Gas Operator | Jun 1995 |
| 693 | Triple "W" Oil Company | Graham, TX 76450 | Oil & Gas Operator | Apr 2026 |
| 694 | Triple 'A' Energy, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Apr 2026 |
| 695 | Triple C Oil Inc. | Lockhart, TX 78644 | Oil Operator | Aug 2019 |
| 696 | Triple Crown Resources, LLC | Dallas, TX 75201 | Oil & Gas Operator | Apr 2026 |
| 697 | Triple D Oil & Gas Co., Inc. | Brownwood, TX 76801 | Oil & Gas Operator | Apr 2026 |
| 698 | Triple G Oil & Gas | Sonora, TX 76950 | Oil & Gas Operator | Oct 2022 |
| 699 | Triple G Well Service, Inc. | Muenster, TX 76252 | Oil & Gas Operator | Apr 2026 |
| 700 | Triple H Production | Stockdale, TX 78160 | Oil Operator | Dec 2025 |