| 801 | Amalgamated Bonanza Petr. LTD. | | Oil & Gas Operator | Apr 1980 |
| 802 | Amalgamated Sludge NM, LLC | Dallas, TX 75208 | Gas Operator | Apr 2026 |
| 803 | Amarex Inc | | Oil & Gas Operator | Dec 1996 |
| 804 | Amarex Incorpora | | Oil Operator | Feb 1985 |
| 805 | Amarillo Exploration, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Jun 2026 |
| 806 | Amarillo Natural Gas, Inc. | Amarillo, TX 79119 | Gas Operator | Jul 1996 |
| 807 | Amarillo Oil Company | | Oil & Gas Operator | Aug 1980 |
| 808 | Amaroq Resources, LLC | | Gas Operator | Mar 2026 |
| 809 | Amata Oils Inc | | Oil Operator | Dec 2015 |
| 810 | Amax Oil & Gas Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 811 | Amax Petroleum C | | Oil & Gas Operator | Aug 1986 |
| 812 | Amax Petroleum Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2012 |
| 813 | Amax Petroluem Corp. | | Oil & Gas Operator | Nov 1983 |
| 814 | Amazon Exploration LLC | | Oil Operator | Apr 2016 |
| 815 | Amazon Royalties, Inc. | Fulshear, TX 77441 | Oil & Gas Operator | Jun 2026 |
| 816 | Ambassador Oil Company, LLC | Abilene, TX 79604 | Oil & Gas Operator | Jun 2026 |
| 817 | Ambassador Petroleum, Inc. | Katy, TX 77494 | Oil & Gas Operator | Jun 2026 |
| 818 | Amber Oil Compan | | Oil Operator | Aug 1995 |
| 819 | Amble Petroleum Co., Inc. | Tuscola, TX 79562 | Oil Operator | Sep 2025 |
| 820 | Ambra Oil & Gas Company | Rangely, CO 81648 | Oil & Gas Operator | Jul 2006 |
| 821 | Ambrit Energy Corp. | Garland, TX 75044 | Oil & Gas Operator | Jun 2003 |
| 822 | Amcole Energy Corporation | Dallas, TX 75231 | Oil & Gas Operator | Aug 2000 |
| 823 | Amcon Resources | Oklahoma City, OK 73102 | Gas Operator | Jul 2000 |
| 824 | Amcon Resources, Inc. | Oklahoma City, OK 73101 | Gas Operator | Jun 2016 |
| 825 | Amedan Resources, Inc. | Chickasha, OK 73023 | Oil & Gas Operator | Mar 2008 |
| 826 | Amelia Exploration LLC | Horseshoe Bay, TX 78657 | Oil Operator | Jun 2026 |
| 827 | Amen Oil LLC | Graham, TX 76450 | Oil & Gas Operator | Jun 2026 |
| 828 | Amend Energy Company | Houston, TX 77227 | Oil & Gas Operator | Apr 2002 |
| 829 | Amer Energy Develop Inc | Columbus, OH 43220 | Oil & Gas Operator | Dec 1989 |
| 830 | Amer Exploration Co | Plymouth Meeting, PA 19462-1640 | Oil & Gas Operator | Dec 2008 |
| 831 | Amer Natural Resources LLC | Rural Valley, PA 16249-0306 | Oil & Gas Operator | Dec 2018 |
| 832 | Amer Oil & Gas LLC | MT Morris, PA 15349 | Oil & Gas Operator | Apr 2026 |
| 833 | Amer-Tex Energy Inc | Oklahoma City, OK 73116-9037 | Oil & Gas Operator | Feb 2012 |
| 834 | Amer. Intl. Petroleum Corp. | | Oil & Gas Operator | Dec 1990 |
| 835 | Amerac Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2013 |
| 836 | Amerada Hess Corp-Placid | | Gas Operator | Sep 1990 |
| 837 | Amerada Hess Corp. Unit Operator | | Oil & Gas Operator | Dec 1986 |
| 838 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 839 | Amerada Hess-Ethyl Corporation | | Oil & Gas Operator | Sep 1990 |
| 840 | Ameredev New Mexico, LLC | Dallas, TX 75240 | Oil & Gas Operator | Dec 2024 |
| 841 | Ameredev Operating, LLC | Austin, TX 78716 | Oil & Gas Operator | Jun 2026 |
| 842 | Amerex Corporation | Edmond, OK 73013-1044 | Oil & Gas Operator | Apr 2020 |
| 843 | American B. C. Resources | | Oil & Gas Operator | Oct 1985 |
| 844 | American Barter Petroleum Inc. | | Oil & Gas Operator | Jun 1993 |
| 845 | American Capital Corporation | San Marcos, CA 92069 | Oil & Gas Operator | Sep 2014 |
| 846 | American Cascade Energy, Inc. | Barker, TX 77413 | Oil & Gas Operator | Jun 2026 |
| 847 | American Casing Crews, Inc. | | Oil Operator | Dec 1979 |
| 848 | American Coastal Energy, Inc. | Houston, TX 77225 | Oil & Gas Operator | May 2008 |
| 849 | American Cometra, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2008 |
| 850 | American Delta Corporation | Portland, TX 78374 | Oil & Gas Operator | Jun 2013 |
| 851 | American Domestic MGMT Inc | Tulsa, OK 74155 | Oil & Gas Operator | Apr 2015 |
| 852 | American Eagle Energy Corporation | | Oil & Gas Operator | Oct 2015 |
| 853 | American Eagle Operating LLC | Gainesville, TX 76240 | Oil Operator | Jun 2026 |
| 854 | American Eagle Operating, Inc. | Spring, TX 77386 | Oil Operator | Aug 2010 |
| 855 | American Eagle Resources, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Jun 2026 |
| 856 | American Energie | | Oil & Gas Operator | May 1995 |
| 857 | American Energies Pipeline, LLC | Dallas, TX 75207 | Oil & Gas Operator | Jan 2015 |
| 858 | American Energy | Abilene, TX 79604 | Oil & Gas Operator | Jul 2004 |
| 859 | American Energy Associates Inc | Cortland, OH 44410 | Oil & Gas Operator | Dec 2025 |
| 860 | American Energy Corporation | Bealsville, OH 43716 | Oil & Gas Operator | Dec 2019 |
| 861 | American Energy Holdings, LLC | Jane Lew, WV 26378 | Oil & Gas Operator | Dec 2021 |
| 862 | American Energy LLC | Lake Zurich, IL 60047-0129 | Oil & Gas Operator | Nov 2014 |
| 863 | American Energy Op. Corp.,The | Houston, TX 77099 | Oil & Gas Operator | Jun 2026 |
| 864 | American Energy Partners, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Dec 2011 |
| 865 | American Energy Recovery Inc | Oklahoma City, OK 73123-0549 | Oil & Gas Operator | Aug 2017 |
| 866 | American Energy Resources, LLC | Belton, MO 64012 | Oil Operator | Dec 2019 |
| 867 | American Energy Sources, Inc. | Spring, TX 77388 | Oil & Gas Operator | Dec 2008 |
| 868 | American Energy Texas Inc | Mineral Wells, TX 76067 | Oil Operator | Jun 2026 |
| 869 | American Energy Utica LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Sep 2015 |
| 870 | American Energy-Perm Basin, LLC | Oklahoma City, OK 73113 | Oil & Gas Operator | May 2016 |
| 871 | American Explora | | Gas Operator | Apr 1994 |
| 872 | American Exploration | Houston, TX 77010 | Gas Operator | Apr 1994 |
| 873 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 874 | American Exploration Oper. Co. | | Oil & Gas Operator | May 1990 |
| 875 | American Explorer, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Jan 1999 |
| 876 | American Helium LLC | | Oil & Gas Operator | Nov 2025 |
| 877 | American Helium Operating, LLC | Katy, TX 77494 | Oil & Gas Operator | Nov 2025 |
| 878 | American Hunter Explor LTD | Calgary Alberta Canada, T2P3H5 | Oil & Gas Operator | Dec 1993 |
| 879 | American Inland Resources Company LLC | Midland, TX 79705 | Oil & Gas Operator | Apr 2005 |
| 880 | American Int'L Energy Corp. | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 881 | American Intl Production Inc. | | Oil & Gas Operator | Apr 1993 |
| 882 | American Land And Energy LLC | Castle Pines, CO 80108 | Oil Operator | Feb 2026 |
| 883 | American Lariat | | Oil Operator | Jun 1994 |
| 884 | American National Petroleum Co. | Houston, TX 77057 | Oil & Gas Operator | Aug 1995 |
| 885 | American Natural Energy Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | Jan 2025 |
| 886 | American Natural Gas Inc | Saint Clairsville, OH 43950 | Oil & Gas Operator | Dec 2020 |
| 887 | American Natural Resources LLC | Tulsa, OK 74145-1117 | Oil & Gas Operator | May 2020 |
| 888 | American Oil & Gas, Inc. | | Oil & Gas Operator | Nov 2010 |
| 889 | American Oilfield Systems, Inc. | Nichols Hill, OK 73116 | Oil & Gas Operator | Jun 2001 |
| 890 | American Operating Company | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2003 |
| 891 | American Petrofina Co Of Texas | | Oil & Gas Operator | Jun 1985 |
| 892 | American Petrofina Co Of TX | Dallas, TX 75221-2159 | Oil & Gas Operator | Nov 2000 |
| 893 | American Petrole | | Oil & Gas Operator | Dec 1996 |
| 894 | American Petroleum & Environmental Consultants Inc | Edmond, OK 73013-8801 | Oil & Gas Operator | Mar 2026 |
| 895 | American Petroleum & Mineral Co Inc | Seminole, OK 74868 | Oil & Gas Operator | Aug 2019 |
| 896 | American Petroleum Corp | Addison, TX 75001 | Oil & Gas Operator | Jun 2026 |
| 897 | American Petroleum Energy Co | | Gas Operator | Apr 2026 |
| 898 | American Pumping & Trucking | New Braunfels, TX 78131 | Oil & Gas Operator | Jun 2026 |
| 899 | American Quasar Petroleum | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 1985 |
| 900 | American Quasar Petroleum Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2014 |