| 801 | Mayhew Properties | | Gas Operator | Sep 2025 |
| 802 | Mayjac I, LLC | Midland, TX 79705 | Oil & Gas Operator | Dec 2025 |
| 803 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 804 | Mayne & Mertz, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2013 |
| 805 | Mayo Oil Co. | San Antonio, TX 78209 | Oil & Gas Operator | Feb 2019 |
| 806 | Mayo Ross L Inc | Oklahoma City, OK 73120-1426 | Oil & Gas Operator | Jan 1997 |
| 807 | Mayo, Danny | Whitesboro, TX 76273 | Oil & Gas Operator | Dec 2025 |
| 808 | Mayo, Eddie | Fredericksbrg, TX 78624 | Oil & Gas Operator | Dec 2025 |
| 809 | Mayo, Keith | Wichita Falls, TX 76301 | Oil & Gas Operator | Sep 2009 |
| 810 | Mayo, Paul R. | Quinlan, TX 75474 | Oil & Gas Operator | May 1999 |
| 811 | Mays Coal Co | Clarion, PA 16214-0447 | Gas Operator | Dec 2003 |
| 812 | Mays Enterprises, Inc. | Mineral Wells, TX 76067 | Gas Operator | Oct 2010 |
| 813 | Mays Gas & Coal Co | Clarion, PA 16214-0447 | Oil & Gas Operator | Dec 2024 |
| 814 | Mays Oil LLC | | Oil Operator | Apr 2021 |
| 815 | Mays, Sam W., Jr. Estate | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2005 |
| 816 | Mayshark, James Page | Sherman, NY 14781 | Gas Operator | Dec 2024 |
| 817 | Mazco Energy LLC | San Antonio, TX 78266 | Oil & Gas Operator | Dec 2025 |
| 818 | Mazel Oil & Gas Co. | Austin, TX 78768 | Gas Operator | Jan 1994 |
| 819 | Mazurkiewicz, Gary, Kimberly, Matt | Perrysburg, NY 14129 | Gas Operator | Dec 2024 |
| 820 | MB Energy, LLC | San Antonio, TX 78233 | Oil & Gas Operator | Dec 2025 |
| 821 | MB Exploration, LLC | Dallas, TX 75380 | Oil & Gas Operator | Jul 2008 |
| 822 | MB Holdings LLC | Independence, KS 67301 | Oil Operator | Sep 2025 |
| 823 | MB Operating | Wichita Falls, TX 76309 | Oil & Gas Operator | Mar 2008 |
| 824 | MBC Operating Co., Inc. | Garland, TX 75042 | Oil & Gas Operator | Aug 1993 |
| 825 | Mbi Oil & Gas LLC | Dickinson, ND 58601 | Oil & Gas Operator | Nov 2025 |
| 826 | MBM Partnership | | Gas Operator | Nov 1991 |
| 827 | MBM Production, LLC | Pikeville, KY 41501 | Oil & Gas Operator | Dec 2023 |
| 828 | Mbo, LLC | | Oil Operator | Jan 2025 |
| 829 | MBR Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Dec 2025 |
| 830 | MBS Resources Inc | Wilcox, PA 15870-1810 | Oil & Gas Operator | Dec 2024 |
| 831 | MBX Operating LLC | Houston, TX 77007 | Oil & Gas Operator | Dec 2025 |
| 832 | MC C Oil Co Inc | Sedan, KS 67361 | Oil Operator | Apr 2016 |
| 833 | MC Glover, LLC | Albany, TX 76430 | Oil Operator | Aug 2025 |
| 834 | MC Oil, LLC | Morganfield, KY 42437 | Oil Operator | Dec 2023 |
| 835 | MC Panhandle, Inc. | Tulsa, OK 74102 | Gas Operator | Jul 1998 |
| 836 | MC1 Consulting, Inc. | San Antonio, TX 78209 | Oil Operator | Sep 2025 |
| 837 | MC123 LLC | Indiana, PA 15701-8718 | Gas Operator | Dec 2024 |
| 838 | McA Petroleum Corporation | Flatonia, TX 78941 | Oil & Gas Operator | Dec 2025 |
| 839 | McAdams Roux & Associates | Denver, CO 80202 | Oil & Gas Operator | Dec 1999 |
| 840 | McAdams, J F | | Oil Operator | May 1971 |
| 841 | McAlester Fuel Co. | Houston, TX 77042 | Oil & Gas Operator | Jan 2010 |
| 842 | McAnear Oil & Gas | Freer, TX 78357 | Oil & Gas Operator | Dec 2002 |
| 843 | McAninch J W | Tonkawa, OK 74653 | Oil & Gas Operator | Nov 2000 |
| 844 | McAninch Michael E | Tonkawa, OK 74653-4415 | Oil & Gas Operator | May 2013 |
| 845 | McAninch W Kent | Tonkawa, OK 74653-4216 | Oil & Gas Operator | Oct 2016 |
| 846 | McBay Company | Grapeland, TX 75844 | Oil & Gas Operator | Feb 2002 |
| 847 | McBee Company, The | Dallas, TX 75219 | Oil & Gas Operator | Dec 1997 |
| 848 | McBee Operating Company, L.L.C. | Dallas, TX 75209 | Oil & Gas Operator | Dec 2025 |
| 849 | McBee, Jim Co. | Santa Anna, TX 76878 | Oil & Gas Operator | Mar 2012 |
| 850 | McBo Oil Co. | | Oil & Gas Operator | Dec 1996 |
| 851 | McBrayer Oil Corporation | Rockport, TX 78381 | Oil & Gas Operator | Nov 1994 |
| 852 | McBride Operating LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 853 | McBride Production Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 1993 |
| 854 | McBride, Jane | Perry, NY 14530 | Gas Operator | Dec 2024 |
| 855 | McBride, Jerrel L Enterprise Inc | Kilgore, TX 75663 | Oil & Gas Operator | Jun 1999 |
| 856 | McBride, Nicholas J. & Holly M. | Lakeland, FL 33810 | Gas Operator | Dec 2024 |
| 857 | McCabe & Co | Albion, PA 16401-8013 | Oil & Gas Operator | Dec 1994 |
| 858 | McCabe Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2009 |
| 859 | McCabe Oil And Gas LLC / Osage Only | | Oil Operator | Oct 2025 |
| 860 | McCabe, William G | | Oil & Gas Operator | Aug 2013 |
| 861 | McCaffery & Krampf Oil Co. | Allegany, NY 14706 | Oil Operator | Dec 2012 |
| 862 | McCall Carl E | Fairmount City, PA 16224 | Oil & Gas Operator | Dec 2024 |
| 863 | McCamey Oil And Gas LLC | MC Camey, TX 79752 | Oil Operator | Dec 2025 |
| 864 | McCammon Oil & Gas, Inc. | San Angelo, TX 76902 | Oil & Gas Operator | Dec 2025 |
| 865 | McCandless Rober | | Oil & Gas Operator | May 1991 |
| 866 | McCandlish R L Oil Co Inc | Bremen, OH 43107 | Oil & Gas Operator | Dec 1997 |
| 867 | McCann Corporation | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 868 | McCann Drilling | | Oil & Gas Operator | Oct 1996 |
| 869 | McCann Drilling, Inc. | Bartlesville, OK 74003 | Oil Operator | Mar 2011 |
| 870 | McCann Mark Wind | | Oil & Gas Operator | Dec 1994 |
| 871 | McCann Petroleum, Inc. | Sedan, KS 67361 | Oil & Gas Operator | Jul 1998 |
| 872 | McCann Resources Inc | | Oil & Gas Operator | Oct 2025 |
| 873 | McCart Sue | Okmulgee, OK 74447 | Oil & Gas Operator | Nov 2024 |
| 874 | McCarter | | Gas Operator | Nov 1996 |
| 875 | McCarter, A. Nelson | Houston, TX 77063 | Oil & Gas Operator | Aug 2003 |
| 876 | McCarter, W. B. Jr. | Houston, TX 77063 | Oil & Gas Operator | Feb 2002 |
| 877 | McCarter-Greenbrier-Macdonald | | Oil Operator | Sep 1981 |
| 878 | McCarthy Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Oct 2007 |
| 879 | McCarthy Oil Co. | | Oil Operator | Dec 1998 |
| 880 | McCarthy Oil Com | | Oil Operator | Jun 1994 |
| 881 | McCarthy Tim W - | | Oil Operator | Mar 1994 |
| 882 | McCarthy, Lawrence J. | Plains, MT 59859-9215 | Oil & Gas Operator | Nov 2011 |
| 883 | McCartney Engineering LLC | Wheat Ridge, CO 80033 | Oil & Gas Operator | Oct 2025 |
| 884 | McCarty Francis | | Oil Operator | Sep 1993 |
| 885 | McCarty, Charles E | Spencer, WV 25276 | Oil & Gas Operator | Dec 2021 |
| 886 | McCaskey, Jeffrey A. | East Aurora, NY 14052 | Gas Operator | Dec 2024 |
| 887 | McCasland Management Inc | Hobbs, NM 88240 | Oil & Gas Operator | Aug 2020 |
| 888 | McCauley Operating Co., Inc. | | Gas Operator | Mar 1999 |
| 889 | McCauley Production | Graham, TX 76450 | Oil Operator | Dec 2025 |
| 890 | McCauley, F. R. | Houston, TX 77002 | Oil & Gas Operator | Apr 2000 |
| 891 | McChesney Michael & Ayo Joseph R | Pinedale, WY 82941-1282 | Oil Operator | Nov 2019 |
| 892 | McClain Oil Co | Granville, OH 43023 | Oil & Gas Operator | Dec 1988 |
| 893 | McClane Energy Inc | | Oil & Gas Operator | Aug 2017 |
| 894 | McCleese Enterprises LLC | Richardson, TX 75082-4839 | Gas Operator | Dec 2017 |
| 895 | McClellan Oil Corporation | Roswell, NM 882020730 | Oil & Gas Operator | May 2015 |
| 896 | McClelland Creek Properties,Inc. | Pampa, TX 79066 | Oil & Gas Operator | Dec 2025 |
| 897 | McClelland Oil - | | Oil Operator | Dec 2009 |
| 898 | McClelland, C.R. Operations, Inc. | Madison, KS 66860 | Oil Operator | Aug 1998 |
| 899 | McClintock V C | Casper, WY 82601 | Oil & Gas Operator | May 2024 |
| 900 | McClintock, Robert T | | Oil & Gas Operator | Oct 2025 |