| 4701 | Triangle Oil Producers, Inc. | | Oil & Gas Operator | Jun 1998 |
| 4702 | Tribal Oil Company | | Oil & Gas Operator | Dec 1981 |
| 4703 | Tricentrol Resources Inc | Englewood, CO 80111 | Oil & Gas Operator | Jun 1984 |
| 4704 | Trich Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2025 |
| 4705 | Trichel Contracting Company | | Oil & Gas Operator | Sep 1987 |
| 4706 | Trickle Down Oil, Inc. | | Oil & Gas Operator | Feb 2016 |
| 4707 | Trico Energy Corporation | | Oil Operator | May 1984 |
| 4708 | Trico Oil & Gas Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Sep 2025 |
| 4709 | Trico Oil Co., Inc. | | Gas Operator | Nov 1978 |
| 4710 | Trident Oil And Gas Corp. | | Oil & Gas Operator | Sep 2000 |
| 4711 | Trigon Exploration, Inc. | | Oil & Gas Operator | Jan 1999 |
| 4712 | Trinidad Petroleum Corporation | | Oil & Gas Operator | Apr 1990 |
| 4713 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 4714 | Trinity Resources, Inc. | Houston, TX 77277 | Oil & Gas Operator | May 2020 |
| 4715 | Trinity River Energy Oper, LLC | Houston, TX 77008 | Oil & Gas Operator | May 2018 |
| 4716 | Triple J Investments Inc | Longview, TX 75606 | Oil & Gas Operator | Feb 2023 |
| 4717 | Triple J Oil Co. | Pampa, TX 79065 | Oil & Gas Operator | Aug 1996 |
| 4718 | Triple L Oil Company | Corpus Chrsti, TX 78469 | Oil & Gas Operator | Jan 1998 |
| 4719 | Triple L Operating Company LLC | Kilgore, TX 75663 | Oil Operator | Sep 2025 |
| 4720 | Triple S Oil Company | | Oil & Gas Operator | Feb 1979 |
| 4721 | Tripower Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2020 |
| 4722 | Tristar Energy 1 | | Oil Operator | Sep 1987 |
| 4723 | Tristate Nla, LLC | | Oil Operator | Dec 2024 |
| 4724 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 4725 | Triumph Energy Inc-P B Berry | | Oil & Gas Operator | Jun 1986 |
| 4726 | Triumph Energy, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2015 |
| 4727 | Troy E. Boyd | | Oil Operator | Oct 1998 |
| 4728 | Trunkline Gas Company | | Oil Operator | Mar 2008 |
| 4729 | Tryvest, Inc. | | Oil & Gas Operator | Sep 1991 |
| 4730 | Tucker Operating Co., Inc. | Victoria, TX 77903 | Oil & Gas Operator | Sep 2025 |
| 4731 | Tulip Industries, Inc. | | Oil & Gas Operator | Feb 2024 |
| 4732 | Tundra Energy | | Oil Operator | Jan 2025 |
| 4733 | Tundra Operating LLC | Spring, TX 77386 | Oil Operator | May 2017 |
| 4734 | Turnkey E&P Corporation | | Oil & Gas Operator | Dec 2010 |
| 4735 | TWC Oil Company | | Oil Operator | Jan 2025 |
| 4736 | Twin City Gas | | Gas Operator | Nov 1997 |
| 4737 | Twiner Oil & Gas Corporation | | Oil & Gas Operator | Oct 1988 |
| 4738 | Two Bayous, Inc. | | Oil & Gas Operator | Dec 2024 |
| 4739 | Txla Energy, Inc. | Houston, TX 77018 | Oil & Gas Operator | Sep 2025 |
| 4740 | Txo Prod Corp.-Arkla Expl. Co. | | Oil & Gas Operator | Dec 1990 |
| 4741 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 4742 | Txo Production Corp/Amh O&G Co | | Oil & Gas Operator | Dec 1990 |
| 4743 | TXP Operating Company | | Oil & Gas Operator | Jul 1992 |
| 4744 | TXX Operating LLC | Shreveport, LA 71133 | Oil & Gas Operator | Sep 2025 |
| 4745 | Ty-Tex Exploration, Inc. | Tyler, TX 75711 | Oil Operator | Dec 2000 |
| 4746 | Tygr Operating Company, LLC | | Oil & Gas Operator | Nov 2024 |
| 4747 | Tyler Production, LLC | | Oil & Gas Operator | Jul 2013 |
| 4748 | Tysco Oil And Gas Corp. | | Oil & Gas Operator | Dec 2024 |
| 4749 | Tyson Oil Co. | | Oil Operator | Jan 2025 |
| 4750 | U R C C | | Oil & Gas Operator | Jun 1991 |
| 4751 | U S Exploraton Liq Trust | | Oil & Gas Operator | Oct 1994 |
| 4752 | U S Liquids Of La., L.P. | | Oil Operator | Apr 2014 |
| 4753 | U. D. Man, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Sep 2025 |
| 4754 | U. O. C., Inc. | | Oil Operator | Jun 2019 |
| 4755 | U. S. Operating, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Jul 2025 |
| 4756 | U.S. Capital Corp Of Am, Inc. | | Oil & Gas Operator | Aug 1998 |
| 4757 | U.S. Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 4758 | Ultramar Oil & Gas LTD | Houston, TX 77060 | Oil & Gas Operator | Jul 1995 |
| 4759 | Ultramar Production Company | | Oil & Gas Operator | Dec 1991 |
| 4760 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 4761 | Uni Production Company, Inc. | | Oil & Gas Operator | Apr 1988 |
| 4762 | Unifid Oil & Gas Corp. | | Oil & Gas Operator | Mar 1994 |
| 4763 | Union Diversified, Inc. | | Gas Operator | Dec 2008 |
| 4764 | Union Drilling &Management Inc | | Gas Operator | Feb 1991 |
| 4765 | Union Exploration Partners, LTD. | | Oil & Gas Operator | Aug 1990 |
| 4766 | Union Gas Operating Company | Houston, TX 77014 | Oil & Gas Operator | Sep 2025 |
| 4767 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 4768 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 4769 | Union Texas Petroleum Corp. | Houston, TX 77252-2120 | Oil & Gas Operator | Dec 2014 |
| 4770 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Sep 2025 |
| 4771 | United Gas Pipe Line Co. | | Oil Operator | Aug 1993 |
| 4772 | United Investment Group | | Oil Operator | Nov 2004 |
| 4773 | United Operators, Inc. | | Oil Operator | Sep 1999 |
| 4774 | United Petroleum Corporation | Edgwater, CO 80214 | Oil & Gas Operator | May 1996 |
| 4775 | United Southern Resources Inc. | | Gas Operator | Nov 2013 |
| 4776 | United World Energy Corporation | | Oil & Gas Operator | Dec 2024 |
| 4777 | Universal Drilling Co., Inc. | Denver, CO 80203 | Oil & Gas Operator | Sep 2003 |
| 4778 | Universal Land | | Oil Operator | Dec 2024 |
| 4779 | Universal Oil Co. | | Oil Operator | Jan 2025 |
| 4780 | Universal Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2002 |
| 4781 | Universal Producers, Inc. | | Oil Operator | Jun 2001 |
| 4782 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 4783 | University Field Management LLC | | Oil Operator | Nov 2024 |
| 4784 | Unocal Exploration Corporation | Houston, TX 77001 | Oil & Gas Operator | May 1992 |
| 4785 | Upstream Exploration LLC | Metairie, LA 70002 | Oil & Gas Operator | Jan 2020 |
| 4786 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Sep 2025 |
| 4787 | Us Liquids Of La, LTD | | Oil Operator | Jul 2002 |
| 4788 | Us Oil & Gas Inc | Marietta, OH 45750 | Oil & Gas Operator | Jul 2025 |
| 4789 | V L Pittman PC & Producer, Inc | | Oil & Gas Operator | Jul 1989 |
| 4790 | V. E. Karnes | | Oil Operator | Jun 1989 |
| 4791 | V. H. Brumley | | Oil Operator | Jul 1994 |
| 4792 | V. Monta Currie, Jr. | | Oil Operator | Jun 2007 |
| 4793 | Vale Petroleum Corporation | Houston, TX 77042 | Gas Operator | Jan 1995 |
| 4794 | Valerius, Inc. & Zine, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Jul 1994 |
| 4795 | Vamos Oil & Gas, LLC | Miami, FL 33129 | Oil & Gas Operator | Sep 2025 |
| 4796 | Van Operating, LTD. | Albany, TX 76430 | Oil & Gas Operator | Sep 2025 |
| 4797 | Van Zanten, Inc. | | Gas Operator | Jan 1990 |
| 4798 | Vanguard Environmental, LLC | | Oil Operator | Nov 2024 |
| 4799 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Feb 2021 |
| 4800 | Vanguard Petroleum Corp. | | Gas Operator | Jun 1986 |