| 901 | Andrews, B. C. | Graham, TX 76450 | Oil & Gas Operator | Sep 2026 |
| 902 | Andries Oil Company | | Oil Operator | Jan 2025 |
| 903 | Andrus Resources Corporation | Houston, TX 77046 | Oil & Gas Operator | Oct 2002 |
| 904 | Anegada Energy LLC | | Gas Operator | May 2026 |
| 905 | Anegada Resources | Kerrville, TX 78029 | Oil & Gas Operator | Jan 2002 |
| 906 | Anejo Production, LLC | Bangs, TX 76823 | Oil & Gas Operator | Sep 2026 |
| 907 | Angel Exploration Company | Oklahoma City, OK 73102-8868 | Oil & Gas Operator | Jan 2019 |
| 908 | Angel Exploration LLC | Oklahoma City, OK 73116-3603 | Oil & Gas Operator | Jun 2026 |
| 909 | Angel Operating LLC | Metairie, LA 70033 | Oil Operator | Sep 2026 |
| 910 | Angel Rose Energy, LLC | Olney, IL 62450 | Oil Operator | Dec 2023 |
| 911 | Angelo, Ernest, Jr. | Midland, TX 79701 | Oil & Gas Operator | Mar 2008 |
| 912 | Angerman Assoc Inc | Pittsburgh, PA 15238-1359 | Oil & Gas Operator | Dec 1998 |
| 913 | Angerman Associates Inc | | Oil & Gas Operator | Mar 1998 |
| 914 | Angie S Parker Dba Parker Cutnose Oil | Sand Springs, OK 74063 | Oil Operator | May 2026 |
| 915 | Angle Exploratio | | Oil Operator | Jan 1987 |
| 916 | Angle George A | | Gas Operator | Dec 1986 |
| 917 | Angle Oil Compan | | Oil Operator | Jun 1994 |
| 918 | Angle Oil Company | Hays, KS 67601 | Oil Operator | Sep 2002 |
| 919 | Anglo Production Company | | Oil & Gas Operator | Nov 1983 |
| 920 | Anglo-Dutch Energy, LLC | | Oil & Gas Operator | Sep 2022 |
| 921 | Angus Energy Inc | Chandler, OK 74834 | Oil & Gas Operator | May 2026 |
| 922 | Angus Energy LLC | Bridgeport, WV 26330 | Oil & Gas Operator | Dec 2025 |
| 923 | Angus Petroleum Corporation | | Oil & Gas Operator | Dec 2022 |
| 924 | Animas Resources, LLC | Hobbs, NM 88240 | Oil & Gas Operator | Jul 2026 |
| 925 | Anisman, Melvin Oil Company Inc. | Pampa, TX 79066 | Oil & Gas Operator | Jun 2003 |
| 926 | Anja Resources | | Oil & Gas Operator | Dec 2021 |
| 927 | Anjet Petroleum Company Inc | Gulfport, MS 39507-1301 | Oil & Gas Operator | Aug 2017 |
| 928 | Ankor E&P Holdings Corporation | | Oil & Gas Operator | Jan 2021 |
| 929 | Anloc, LLC | Houston, TX 77024 | Oil & Gas Operator | Apr 2019 |
| 930 | Ann Brindle | | Oil Operator | Jun 2026 |
| 931 | Ann Marie Tiers | | Oil Operator | Dec 1996 |
| 932 | Annarock Petroleum LLC | Winter Garden, FL 34787 | Oil & Gas Operator | Dec 2025 |
| 933 | Annco Pet. Co & Equipment, Inc | | Oil & Gas Operator | Sep 1982 |
| 934 | Annex Oil Corp | | Oil & Gas Operator | Jun 2000 |
| 935 | Annona Productions, Inc. | | Gas Operator | May 2019 |
| 936 | Anr Limited Inc/Coastal | Houston, TX 770460995 | Oil & Gas Operator | Dec 1987 |
| 937 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 938 | Ansbro Petroleum Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2008 |
| 939 | Anschutz Corporation, The | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 940 | Anschutz Drilling Co. | | Oil Operator | Jul 1961 |
| 941 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2026 |
| 942 | Anschutz Oil Co. | | Oil & Gas Operator | Jul 1984 |
| 943 | Anshutz Oil | | Oil Operator | Dec 2009 |
| 944 | Anson Charles Dba Anson Oil | Seminole, OK 74868 | Oil Operator | May 2026 |
| 945 | Anson Company | Oklahoma City, OK 73124 | Oil & Gas Operator | Apr 2018 |
| 946 | Anson Gas Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | May 1997 |
| 947 | Anson J W | Seminole, OK 74818-1280 | Oil & Gas Operator | Oct 2020 |
| 948 | Anson Robert L & Teresa M | Seminole, OK 74868 | Oil & Gas Operator | May 2026 |
| 949 | Anstine & Musgrove Inc | Ponca City, OK 74602 | Oil & Gas Operator | May 2026 |
| 950 | Anstine Oil Company | | Oil Operator | Apr 2026 |
| 951 | Anstine-Musgrove | Ponca City, OK 74602 | Oil & Gas Operator | Feb 2017 |
| 952 | Anstine-Musgrove Oil Company | Ponca City, OK 74602-0391 | Oil & Gas Operator | Jan 2013 |
| 953 | Ansythe Exploration Co., Inc. | | Oil & Gas Operator | Oct 1982 |
| 954 | Antara Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 955 | Antares Energy Company | Houston, TX 77010 | Oil & Gas Operator | Sep 2026 |
| 956 | Antares Oil Corp | Denver, CO 80202 | Oil & Gas Operator | Oct 2015 |
| 957 | Antares Ventures, L.L.C. | | Oil Operator | Oct 2016 |
| 958 | Antelope Energy Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Nov 2024 |
| 959 | Antelope Energy Partners, LLC | Houston, TX 77027 | Oil & Gas Operator | Sep 2026 |
| 960 | Antelope Production Co. | Midland, TX 79701 | Oil & Gas Operator | Oct 1995 |
| 961 | Antelope Resources, Inc. | Billings, MT 59101 | Oil Operator | May 2017 |
| 962 | Antero Resources Bluestone LLC | | Gas Operator | Dec 2013 |
| 963 | Antero Resources Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 964 | Antero Resources I, LP | Denver, CO 80202 | Oil & Gas Operator | Jun 2005 |
| 965 | Antero Resources II, LP | Denver, CO 80202 | Oil & Gas Operator | May 2006 |
| 966 | Anterra Energy Services Inc. | | Oil & Gas Operator | Dec 2025 |
| 967 | Anterra Services Inc. | | Oil & Gas Operator | Jul 2026 |
| 968 | Anthem Energy Operating (Oklahoma) LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2026 |
| 969 | Anthony Oil Company | | Oil & Gas Operator | Oct 1987 |
| 970 | Anthony, Bob G. Inc. | Brookhaven, MS 39601 | Oil & Gas Operator | Sep 2026 |
| 971 | Antilley, Joe | Abilene, TX 79602 | Oil & Gas Operator | Jan 2024 |
| 972 | Antioch Disposal Well Inc | Duncan, OK 73533 | Oil Operator | Jan 1994 |
| 973 | Antioch Operating LLC | Dallas, TX 75206 | Oil & Gas Operator | Jun 2026 |
| 974 | Antle Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Sep 2026 |
| 975 | Antle, E. | Graham, TX 76450 | Oil & Gas Operator | Oct 1994 |
| 976 | Antler Energy LLC | | Oil & Gas Operator | Apr 2026 |
| 977 | Antlers Energy LLC | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2026 |
| 978 | Antrim Development Corp | | Oil & Gas Operator | Oct 2018 |
| 979 | Anvil Oil Co., Inc. | Bartlesville, OK 74003-5030 | Oil & Gas Operator | Dec 2008 |
| 980 | Anzalone, James A. | Leesburg, FL 34748 | Gas Operator | Dec 2025 |
| 981 | Aoco Operating Company, L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Feb 2005 |
| 982 | Aoco Operating, L.P. | Houston, TX 77008 | Oil & Gas Operator | Mar 2008 |
| 983 | Aocswd LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2025 |
| 984 | Aog Operating LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | May 2026 |
| 985 | Aog, Inc. | Norman, OK 73070 | Oil & Gas Operator | Nov 2014 |
| 986 | Aogp, LLC | Turtle Lake, WI 54889 | Oil & Gas Operator | Sep 2019 |
| 987 | Aop Operating Corporation | Dallas, TX 75313 | Oil & Gas Operator | Aug 2003 |
| 988 | Ap Operating LLC | Claflin, KS 67525 | Oil Operator | Mar 2026 |
| 989 | Ap Operating, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Sep 2026 |
| 990 | Ap Production LLC | Utica, OH 43080 | Oil & Gas Operator | Dec 2025 |
| 991 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Sep 2026 |
| 992 | Apache Drilling | | Oil Operator | Sep 1994 |
| 993 | Apache Drilling Co | Kingman, KS 67068 | Oil Operator | Feb 2006 |
| 994 | Apache Energy Resources Corp. | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 995 | Apache Natural Gas Co., Inc. | | Oil Operator | Nov 1992 |
| 996 | Apache Oil Company | San Antonio, TX 78227 | Oil & Gas Operator | Jun 2023 |
| 997 | Apache PHN North America, Inc. | | Oil & Gas Operator | Mar 2005 |
| 998 | Apache Production Company | Holliday, TX 76366 | Oil & Gas Operator | Sep 2026 |
| 999 | Apache Shelf, Inc. | Houston, TX 77056 | Oil & Gas Operator | Jan 2014 |
| 1000 | Apb Oil Corporation | Houston, TX 77052 | Oil & Gas Operator | Apr 1996 |