| 801 | The Ohio Oil Company | | Oil Operator | Jan 2025 |
| 802 | The Operating Co. | Pampa, TX 79065 | Oil & Gas Operator | Sep 2007 |
| 803 | The Ozark Corp. | | Oil Operator | Apr 1970 |
| 804 | The Pioneer | | Gas Operator | Feb 2008 |
| 805 | The Port Of Long Beach | | Oil & Gas Operator | Dec 1997 |
| 806 | The Procter And Gamble Co. | | Gas Operator | Dec 1989 |
| 807 | The Production Co | Ligonier, PA 15658-0467 | Oil & Gas Operator | Dec 2012 |
| 808 | The Production Co LLC | Ligonier, PA 15658-0467 | Oil & Gas Operator | Dec 2020 |
| 809 | The Pyramid Corporation, Inc. | Wichita, KS 67206 | Oil & Gas Operator | Dec 2009 |
| 810 | The Quintin Little Company Inc | Ardmore, OK 73401 | Oil & Gas Operator | Feb 2025 |
| 811 | The Raven Company LLC | Granbury, TX 76049 | Oil Operator | Mar 2010 |
| 812 | The Richardson Petroleum Corporation | Whitesville, NY 14897 | Oil & Gas Operator | Dec 2023 |
| 813 | The Robert And Donna Harwood Income Only Trust | Perry, NY 14530 | Gas Operator | Dec 2023 |
| 814 | The Romanoff Corporation | | Oil & Gas Operator | Nov 1989 |
| 815 | The Southern Louisiana Expl. Company LLC | | Oil & Gas Operator | Nov 2024 |
| 816 | The Stone Oil Corporation | | Oil & Gas Operator | May 1985 |
| 817 | The Stone Petro Corp-Toce Oil | | Oil & Gas Operator | Oct 1984 |
| 818 | The Superior Oc WM Scully Etal | | Oil & Gas Operator | Apr 1986 |
| 819 | The Superior Oil Co & Pel-Tex | | Oil & Gas Operator | Apr 1986 |
| 820 | The Superior Oil Co - Tesoro | | Oil & Gas Operator | Apr 1986 |
| 821 | The Termo Company | Long Beach, CA 90801 | Oil & Gas Operator | Feb 2025 |
| 822 | The Texas Company | FT Worth, TX 76101 | Oil & Gas Operator | Dec 2013 |
| 823 | The Trees Oil Company | Wichita, KS 67208 | Oil & Gas Operator | Nov 2014 |
| 824 | The Twenty Eleven Corp Inc | Ada, OK 74820-3605 | Oil Operator | Jan 2025 |
| 825 | The Warren Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Jan 2016 |
| 826 | The William R Earnhardt Company | Bristow, OK 74010 | Oil & Gas Operator | Jan 2025 |
| 827 | The WM G Helis Company, L.L.C. | | Oil & Gas Operator | Nov 2003 |
| 828 | The Woods Parcel, LLC | Orchard Park, NY 14127 | Gas Operator | Dec 2023 |
| 829 | Theisen, VIncent A. | Wilmington, DE 19807 | Oil & Gas Operator | Sep 2003 |
| 830 | Theodore W Ochs | Lucinda, PA 16235-3517 | Gas Operator | Dec 2009 |
| 831 | Third Coast Energy, Inc. | Corpus Chrsti, TX 78427 | Oil & Gas Operator | Apr 2025 |
| 832 | Tholl Oil Company | | Oil Operator | Dec 2003 |
| 833 | Thomas A. Blanton | | Oil Operator | Nov 2024 |
| 834 | Thomas Aitken, Inc. | | Gas Operator | Dec 2024 |
| 835 | Thomas And Ruby Parkinson Trust | Tatum, NM 88267 | Oil & Gas Operator | Feb 2025 |
| 836 | Thomas B Rixleben | | Oil & Gas Operator | Jul 2008 |
| 837 | Thomas Bell | | Oil Operator | Dec 1985 |
| 838 | Thomas C. Hoffpauir | | Oil & Gas Operator | Mar 1991 |
| 839 | Thomas C. Hoffpauir, Inc. | | Oil & Gas Operator | Jan 1981 |
| 840 | Thomas C. King | | Oil & Gas Operator | Dec 1995 |
| 841 | Thomas E L | Tulsa, OK 74136-6302 | Oil & Gas Operator | Feb 2015 |
| 842 | Thomas E. Slack | | Oil Operator | Mar 2003 |
| 843 | Thomas Exploration & Devel., Inc | Jourdanton, TX 78026 | Oil & Gas Operator | Apr 2025 |
| 844 | Thomas Exploration Company | Tulsa, OK 74136-6302 | Oil & Gas Operator | Jan 2025 |
| 845 | Thomas G. Easterling | | Oil Operator | Jun 1989 |
| 846 | Thomas Garner, Inc. | St John, KS 67576 | Oil & Gas Operator | Dec 2024 |
| 847 | Thomas J L Engineering Inc | Edmond, OK 73003-0026 | Oil & Gas Operator | Jul 2016 |
| 848 | Thomas L Spring LLC | | Oil & Gas Operator | Feb 2025 |
| 849 | Thomas M. Brown LLC | Plainville, KS 67663 | Oil Operator | Dec 2024 |
| 850 | Thomas Oil & Gas Company | Luling, TX 78648 | Oil & Gas Operator | Aug 2003 |
| 851 | Thomas Oil And Gas Inc. | San Angelo, TX 76906 | Oil & Gas Operator | May 2019 |
| 852 | Thomas Oil Company | | Oil & Gas Operator | Dec 2008 |
| 853 | Thomas Oil Company LLC | Ardmore, OK 73401-3717 | Oil Operator | Feb 2025 |
| 854 | Thomas Oilers | | Oil & Gas Operator | Dec 2024 |
| 855 | Thomas Operating Company Inc | Greeley, CO 80634 | Oil & Gas Operator | Aug 2008 |
| 856 | Thomas Operating LTD. Co. | Dallas, TX 75220 | Oil & Gas Operator | Apr 2025 |
| 857 | Thomas Production | Electra, TX 76360 | Oil & Gas Operator | Mar 2015 |
| 858 | Thomas Production Co Inc | | Oil & Gas Operator | Mar 2015 |
| 859 | Thomas R Sivley | Southlake, TX 76092 | Oil & Gas Operator | Mar 2013 |
| 860 | Thomas R. Banks | | Oil Operator | Dec 2024 |
| 861 | Thomas Resources Corporation | Monahans, TX 79756 | Oil Operator | Mar 2008 |
| 862 | Thomas Steel Strip Corp | Warren, OH 44485 | Oil & Gas Operator | Dec 2024 |
| 863 | Thomas Turman | | Oil & Gas Operator | Dec 1991 |
| 864 | Thomas Wayne Oil & Gas | Bristow, OK 74010-0544 | Oil & Gas Operator | Jan 2018 |
| 865 | Thomas Well Serv | | Oil Operator | Dec 1996 |
| 866 | Thomas Well Service, Inc. | Easton, KS 66020 | Oil Operator | Dec 2024 |
| 867 | Thomas, B. K. | Plano, TX 75093 | Oil & Gas Operator | Jan 2008 |
| 868 | Thomas, Ellis W | | Oil & Gas Operator | Jan 2025 |
| 869 | Thomas, M.A. Oil Associates | Nocona, TX 76255 | Oil & Gas Operator | Apr 2025 |
| 870 | Thomas, Mike | Nixon, TX 78140 | Oil Operator | Apr 2025 |
| 871 | Thomas, R. W. Inc. | Norman, OK 73070 | Oil & Gas Operator | Apr 2015 |
| 872 | Thomas, T. N. Oil Company | Aiken, SC 29801 | Oil & Gas Operator | Apr 2025 |
| 873 | Thomas, Vernon C. | Gardner, KS 66030 | Oil Operator | Jun 2015 |
| 874 | Thomason Oil Com | | Oil Operator | Oct 1984 |
| 875 | Thomason Petroleum, Inc | Hays, KS 67601 | Oil Operator | Dec 2024 |
| 876 | Thomasson Petroleum Enterprises, Inc | Bremen, KY 42325 | Oil Operator | Dec 2018 |
| 877 | Thompson & James Cleo Thompson, Jr.* & J Cleo | | Oil & Gas Operator | Jan 2010 |
| 878 | Thompson Consumer Electronics | Indianapolis, IN 46290 | Oil & Gas Operator | Dec 1998 |
| 879 | Thompson Drilling Company, Inc. | Independence, KS 67301 | Oil Operator | Sep 2001 |
| 880 | Thompson Energy Resources LLC | | Oil & Gas Operator | Dec 2024 |
| 881 | Thompson Engr & Prod Corp | Farmington, NM 87402 | Oil & Gas Operator | Apr 2019 |
| 882 | Thompson Felton | Dewey, OK 74029 | Oil Operator | Jul 1999 |
| 883 | Thompson Floyd Oil Co Inc | Boca Raton, FL 44328 | Oil & Gas Operator | Dec 1988 |
| 884 | Thompson James R | Okmulgee, OK 74447 | Oil & Gas Operator | Jan 2025 |
| 885 | Thompson Oil Co. | Corsicana, TX 75151 | Oil & Gas Operator | Dec 2024 |
| 886 | Thompson Operating Co. | Abernathy, TX 79311 | Oil & Gas Operator | Aug 1994 |
| 887 | Thompson Roy G | Bartlesville, OK 74006 | Oil & Gas Operator | Feb 1993 |
| 888 | Thompson, Diana & Glenn | Fredonia, NY 14063 | Gas Operator | Dec 2023 |
| 889 | Thompson, Don W | Herington, KS 67449 | Oil Operator | Jul 2003 |
| 890 | Thompson, J C | Denver, CO 80237-2843 | Oil & Gas Operator | Jul 2005 |
| 891 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 892 | Thompson, Joe L., Inc. | Oklahoma City, OK 73132 | Oil & Gas Operator | Oct 2005 |
| 893 | Thompson, Kenneth L | Clarence Center, NY 14032 | Gas Operator | Dec 2023 |
| 894 | Thompson, Larry N. Revocable Trust, Uid 5-20, 1997 | Elkhart, KS 67950 | Gas Operator | Sep 2006 |
| 895 | Thompson, Mark P. | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 896 | Thompson, Mark V. | South Dayton, NY 14138 | Gas Operator | Dec 2023 |
| 897 | Thompson, Richard W. Inc. | Plano, TX 75024 | Oil & Gas Operator | Apr 2025 |
| 898 | Thompson, Timothy G. | Delevan, NY 14042 | Gas Operator | Dec 2023 |
| 899 | Thomsen Brothers Co., LLC | Lamont, KS 66855 | Oil Operator | Dec 2024 |
| 900 | Thor Operating Company | Tyler, TX 75710 | Oil & Gas Operator | Dec 1995 |