| 2801 | Maddox Oil & Gas | | Gas Operator | Jun 1982 |
| 2802 | Maddox Oil & Gas, Inc. | | Oil Operator | Apr 1983 |
| 2803 | Magic Circle Energy | Oklahoma City, OK 73185 | Oil & Gas Operator | Dec 1983 |
| 2804 | Magna Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 2805 | Magnolia Production Company LLC | | Oil & Gas Operator | Nov 2024 |
| 2806 | Magnum Engineering Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2025 |
| 2807 | Magnum Gas Pipeline, L.L.C. | | Oil Operator | Dec 2024 |
| 2808 | Magnum Hunter Resources Corporation | | Oil & Gas Operator | Nov 2019 |
| 2809 | Magnum Minerals, Inc. | | Oil & Gas Operator | May 1998 |
| 2810 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 2811 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2025 |
| 2812 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 2813 | Majestic Energy Corporation | Shreveport, LA 71164 | Oil & Gas Operator | May 2013 |
| 2814 | Mako Exploration Management, LLC | Shreveport, LA 71105 | Oil & Gas Operator | Apr 2025 |
| 2815 | Mallard Drilling Corp. | | Oil & Gas Operator | Jan 1993 |
| 2816 | Mallard Operating LLC | | Oil & Gas Operator | Nov 2024 |
| 2817 | Mallard Petroleum, Inc. | | Oil & Gas Operator | Apr 1986 |
| 2818 | Malmac Energy Corp. | | Oil & Gas Operator | Jul 1987 |
| 2819 | Malone Oil & Gas Exploration, Inc. | | Oil Operator | Dec 2018 |
| 2820 | Malone-Killen Oil Expl. Co. | | Oil Operator | Apr 1992 |
| 2821 | Mammoth Service Group, LLC | | Oil & Gas Operator | Jan 2025 |
| 2822 | Mandalay Oil & Gas, L.L.C. | | Oil & Gas Operator | May 2008 |
| 2823 | Mandalay Trading Services Inc. | | Oil Operator | Jul 1999 |
| 2824 | Mandina & Murphy Oil Company | | Oil Operator | Nov 1990 |
| 2825 | Mann Production Co., Inc. | | Oil Operator | Nov 1995 |
| 2826 | Manna Minerals, Inc. | | Oil & Gas Operator | Apr 1989 |
| 2827 | Mannon L. Walters, Inc. | | Oil & Gas Operator | Jun 2024 |
| 2828 | Manolo Energy, Inc. | | Oil Operator | Sep 1996 |
| 2829 | Manorado Oil Company | | Oil Operator | Feb 1999 |
| 2830 | Manti Exploration Operating LLC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Feb 2015 |
| 2831 | Manti Operating Company | Covington, LA 70435 | Oil & Gas Operator | Apr 2025 |
| 2832 | Mantle Oil & Gas, LLC | Friendswood, TX 77546 | Oil & Gas Operator | Apr 2025 |
| 2833 | Manursing Island Prod. Corp. | | Oil & Gas Operator | Sep 2002 |
| 2834 | Map Associates, L.P. | | Oil & Gas Operator | Mar 1995 |
| 2835 | Map Drilling Company | | Oil & Gas Operator | Apr 2012 |
| 2836 | Map Oil Co. | | Oil Operator | Jan 1978 |
| 2837 | Mapco Oil & Gas Company | Tulsa, OK 74101-2115 | Oil & Gas Operator | Jan 1985 |
| 2838 | Mapco Production Co | Billings, MT 59102 | Oil & Gas Operator | Apr 1994 |
| 2839 | Maple Gulf Coast Props. Corp. | | Oil & Gas Operator | Jun 1989 |
| 2840 | Mar-Bec Energy Company, L.L.C. | Shreveport, LA 71105 | Oil & Gas Operator | May 2001 |
| 2841 | Mar-Low Corporation | | Oil & Gas Operator | Mar 1992 |
| 2842 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 2843 | Marathon Corporation | | Oil Operator | Dec 1994 |
| 2844 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Feb 2025 |
| 2845 | Marathon Oil Company/Fina | | Oil & Gas Operator | Jan 2005 |
| 2846 | Marben Corporation | | Oil Operator | Jul 1995 |
| 2847 | Marine Cont. & Supply Inc. | | Oil & Gas Operator | Nov 1985 |
| 2848 | Marine Properties, Inc. | | Oil & Gas Operator | Feb 1995 |
| 2849 | Mariner Energy, Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 2850 | Marion Corporation | | Oil & Gas Operator | Jan 2001 |
| 2851 | Maritech Resources, LLC | | Oil & Gas Operator | May 2011 |
| 2852 | Marjo, Inc. | | Oil & Gas Operator | Sep 1991 |
| 2853 | Mark F Preddy & Associates,Inc | | Oil & Gas Operator | Dec 1987 |
| 2854 | Mark L Shidler Inc | Houston, TX 77055 | Oil & Gas Operator | Feb 2025 |
| 2855 | Mark Producing, Inc. | Houston, TX 77057 | Oil & Gas Operator | Dec 1987 |
| 2856 | Mark Seifer | | Oil & Gas Operator | Dec 2024 |
| 2857 | Mark V Petroleum Company | | Oil & Gas Operator | Feb 2020 |
| 2858 | Marks Operating LLC | | Oil & Gas Operator | Jul 2016 |
| 2859 | Marlan Anderson | | Oil Operator | Jan 2025 |
| 2860 | Marlin And Davis | | Oil Operator | Sep 1987 |
| 2861 | Marlin Coastal, L.L.C. | | Oil & Gas Operator | Apr 2008 |
| 2862 | Marlin Energy Offshore, L.L.C. | | Oil & Gas Operator | Jun 2006 |
| 2863 | Marlin Expl.,Inc&Exchg O&G Co | | Oil & Gas Operator | Jun 1987 |
| 2864 | Marlin Exploration, Inc. | | Oil & Gas Operator | Oct 2006 |
| 2865 | Marlin Exploration, LLC | | Oil & Gas Operator | Jan 2025 |
| 2866 | Marlin Resources, L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Jan 2025 |
| 2867 | Marline Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 1989 |
| 2868 | Marline Petroleum Corporation | | Oil & Gas Operator | Dec 1985 |
| 2869 | Marmaton Oil Company | Houston, TX 77002 | Oil & Gas Operator | Jul 1998 |
| 2870 | Maroski, Inc. | | Oil Operator | Jan 1989 |
| 2871 | Marquee Corporation | Houston, TX 77024 | Oil & Gas Operator | Apr 2025 |
| 2872 | Marquis Resources, LLC | | Oil & Gas Operator | Jul 2021 |
| 2873 | Marr Company | | Oil & Gas Operator | Mar 1989 |
| 2874 | Marsh Engineering, Inc. | | Oil & Gas Operator | Dec 1990 |
| 2875 | Marshall & McCain | | Oil & Gas Operator | Oct 1988 |
| 2876 | Marshall Exploration, Inc. | | Oil & Gas Operator | Jun 1992 |
| 2877 | Marshall Petroleum, Inc. | Houston, TX 77040 | Oil & Gas Operator | Aug 2003 |
| 2878 | Marshall Prod. & Energy Inc. | | Oil & Gas Operator | Jan 1992 |
| 2879 | Marshland Exploration Company | | Oil & Gas Operator | May 2006 |
| 2880 | Martin Energy LLC | | Oil & Gas Operator | Apr 2023 |
| 2881 | Martin Exploration Co. | | Oil & Gas Operator | Apr 1986 |
| 2882 | Martin Oil & Gas Co. | | Oil Operator | Jul 1981 |
| 2883 | Martin Oil Co. | Aspermont, TX 79502 | Oil & Gas Operator | Jul 2023 |
| 2884 | Martin Production Company | | Oil & Gas Operator | Dec 2024 |
| 2885 | Martin-Marks Operating Co. LLC | | Oil & Gas Operator | Dec 2010 |
| 2886 | Martineau Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Jan 2025 |
| 2887 | Marvin L. Muslow | | Oil Operator | Jun 1995 |
| 2888 | Mass Resources, Inc. | | Oil Operator | Jan 2025 |
| 2889 | Master Well Works, Inc. | | Oil Operator | Dec 2024 |
| 2890 | Masters Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2008 |
| 2891 | Matador Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2003 |
| 2892 | Matador Production Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2025 |
| 2893 | Matrix Oil & Gas, Inc. | | Oil & Gas Operator | Jul 2001 |
| 2894 | Matrix Production Company | Sugar Land, TX 77478 | Oil & Gas Operator | Feb 2025 |
| 2895 | Matthews Operating Co., Inc. | | Gas Operator | Aug 2001 |
| 2896 | Matthews-Bunn Operating Co. | | Oil & Gas Operator | Apr 1981 |
| 2897 | Matzinger & Bell Inc-Carl O&G | | Oil & Gas Operator | Dec 1981 |
| 2898 | Matzinger & Bell, Inc. | | Oil & Gas Operator | Dec 1982 |
| 2899 | Matzinger Expl Co& Texas Crude | | Oil & Gas Operator | Jun 1980 |
| 2900 | Matzinger Petroleum Co. | | Oil & Gas Operator | Jan 1991 |