| 2801 | Mark V Petroleum Company | | Oil & Gas Operator | Feb 2020 |
| 2802 | Marks Operating LLC | | Oil & Gas Operator | Jul 2016 |
| 2803 | Marlan Anderson | | Oil Operator | Jan 2025 |
| 2804 | Marlin And Davis | | Oil Operator | Sep 1987 |
| 2805 | Marlin Coastal, L.L.C. | | Oil & Gas Operator | Apr 2008 |
| 2806 | Marlin Energy Offshore, L.L.C. | | Oil & Gas Operator | Jun 2006 |
| 2807 | Marlin Expl.,Inc&Exchg O&G Co | | Oil & Gas Operator | Jun 1987 |
| 2808 | Marlin Exploration, Inc. | | Oil & Gas Operator | Oct 2006 |
| 2809 | Marlin Exploration, LLC | | Oil & Gas Operator | Feb 2026 |
| 2810 | Marlin Resources, L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Jan 2025 |
| 2811 | Marline Oil Corp | Houston, TX 77002 | Oil & Gas Operator | Dec 1989 |
| 2812 | Marline Petroleum Corporation | | Oil & Gas Operator | Dec 1985 |
| 2813 | Marmaton Oil Company | Houston, TX 77002 | Oil & Gas Operator | Jul 1998 |
| 2814 | Maroski, Inc. | | Oil Operator | Jan 1989 |
| 2815 | Marquee Corporation | Houston, TX 77024 | Oil & Gas Operator | May 2026 |
| 2816 | Marquis Resources, LLC | | Oil & Gas Operator | Jul 2021 |
| 2817 | Marr Company | | Oil & Gas Operator | Mar 1989 |
| 2818 | Marsh Engineering, Inc. | | Oil & Gas Operator | Dec 1990 |
| 2819 | Marshall & McCain | | Oil & Gas Operator | Oct 1988 |
| 2820 | Marshall Exploration, Inc. | | Oil & Gas Operator | Jun 1992 |
| 2821 | Marshall Petroleum, Inc. | Houston, TX 77040 | Oil & Gas Operator | Aug 2003 |
| 2822 | Marshall Prod. & Energy Inc. | | Oil & Gas Operator | Jan 1992 |
| 2823 | Marshland Exploration Company | | Oil & Gas Operator | May 2006 |
| 2824 | Martin Energy LLC | | Oil & Gas Operator | Apr 2023 |
| 2825 | Martin Exploration Co. | | Oil & Gas Operator | Apr 1986 |
| 2826 | Martin Oil & Gas Co. | | Oil Operator | Jul 1981 |
| 2827 | Martin Oil Co. | Aspermont, TX 79502 | Oil & Gas Operator | Jul 2023 |
| 2828 | Martin Production Company | | Oil & Gas Operator | Dec 2024 |
| 2829 | Martin-Marks Operating Co. LLC | | Oil & Gas Operator | Dec 2010 |
| 2830 | Martineau Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Jan 2025 |
| 2831 | Marvin L. Muslow | | Oil Operator | Jun 1995 |
| 2832 | Mass Resources, Inc. | | Oil Operator | Jan 2025 |
| 2833 | Master Well Works, Inc. | | Oil Operator | Dec 2024 |
| 2834 | Masters Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2008 |
| 2835 | Matador Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2003 |
| 2836 | Matador Production Company | Dallas, TX 75240 | Oil & Gas Operator | May 2026 |
| 2837 | Matrix Oil & Gas, Inc. | | Oil & Gas Operator | Jul 2001 |
| 2838 | Matrix Production Company | Sugar Land, TX 77478 | Oil & Gas Operator | Mar 2026 |
| 2839 | Matthews Operating Co., Inc. | | Gas Operator | Aug 2001 |
| 2840 | Matzinger & Bell Inc-Carl O&G | | Oil & Gas Operator | Dec 1981 |
| 2841 | Matzinger & Bell, Inc. | | Oil & Gas Operator | Dec 1982 |
| 2842 | Matzinger Petroleum Co. | | Oil & Gas Operator | Jan 1991 |
| 2843 | Maurine B. Pyle | | Oil & Gas Operator | Mar 1993 |
| 2844 | Maverick Oil Co. | Richland, TX 76681 | Oil Operator | May 2026 |
| 2845 | Maverick Oil Corp. | | Oil Operator | May 1997 |
| 2846 | Maverick Producers, Inc. | | Oil Operator | May 2012 |
| 2847 | Maxim Energy Corporation | Baytown, TX 77520 | Oil & Gas Operator | Feb 2026 |
| 2848 | Maximus Operating, LTD. | Kilgore, TX 75663 | Oil & Gas Operator | May 2026 |
| 2849 | Maxum Energy Corp | Plano, TX 75025 | Oil & Gas Operator | Jan 2003 |
| 2850 | Maxus Exploration Company | Dallas, TX 75201 | Oil & Gas Operator | Jan 1995 |
| 2851 | Maxwell Oil & Gas Corp. | Kilgore, TX 75663 | Oil & Gas Operator | Jan 2001 |
| 2852 | May Oil & Gas, L.L.C. | | Oil & Gas Operator | Dec 2013 |
| 2853 | May Petroleum Inc | Dallas, TX 75231 | Oil & Gas Operator | Nov 1998 |
| 2854 | Maybrier Brothers | | Oil Operator | Apr 2006 |
| 2855 | Maybrier Production, L.L.C. | | Oil Operator | Oct 2022 |
| 2856 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 2857 | Mayne & Mertz, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2013 |
| 2858 | MBM Partnership | | Gas Operator | Nov 1991 |
| 2859 | Mbo, LLC | | Oil Operator | Jan 2025 |
| 2860 | McAlester Fuel Co. | Houston, TX 77042 | Oil & Gas Operator | Jan 2010 |
| 2861 | McBrayer Oil Corporation | Rockport, TX 78381 | Oil & Gas Operator | Nov 1994 |
| 2862 | McCarter-Greenbrier-Macdonald | | Oil Operator | Sep 1981 |
| 2863 | McClinton & 4-M Invest Inc | | Oil & Gas Operator | Aug 1992 |
| 2864 | McClinton & Mosing | | Oil & Gas Operator | Oct 1977 |
| 2865 | McConathy & Associates | | Oil & Gas Operator | Dec 1983 |
| 2866 | McConathy Production Co.,Inc. | | Oil & Gas Operator | Jun 1990 |
| 2867 | McCord Exploration Co. | | Oil & Gas Operator | Dec 1990 |
| 2868 | McCord Oil Co. And T. Walker | | Oil & Gas Operator | Dec 1985 |
| 2869 | McCord-Dale Exploration | | Oil & Gas Operator | May 1986 |
| 2870 | McCord-Goodrich Oil Company | | Oil & Gas Operator | Oct 1991 |
| 2871 | McCormick Operating Company | | Oil & Gas Operator | Mar 1984 |
| 2872 | McCormick Operating PRTNSHP | | Oil & Gas Operator | Sep 1985 |
| 2873 | McCormick Production Co, Inc. | Oil City, LA 71061 | Oil & Gas Operator | May 2026 |
| 2874 | McCormick-Bintliff | | Oil & Gas Operator | Feb 1984 |
| 2875 | McCormick-Bintliff-Pettit | | Oil & Gas Operator | Feb 1984 |
| 2876 | McCormick-Ciroco, Inc. | | Oil & Gas Operator | Jan 1984 |
| 2877 | McCormick-Terra-Bintliff | | Oil & Gas Operator | Dec 1979 |
| 2878 | McCormick-WHB | | Gas Operator | Jan 1984 |
| 2879 | McCulloch Oil Corp.-Ids | | Oil & Gas Operator | Dec 1981 |
| 2880 | McCurdy Oil Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2025 |
| 2881 | McDaniel Petroleum Company, Inc. | | Oil Operator | Jun 2020 |
| 2882 | McDowell And Cook, Inc. | | Oil Operator | Jan 1987 |
| 2883 | McFarland Energy, Inc. | New Orleans, LA 70160 | Oil & Gas Operator | Dec 2009 |
| 2884 | McGoldrick & Watson | | Oil & Gas Operator | Jul 1987 |
| 2885 | McGoldrick & Watson - Alagood | | Oil Operator | Oct 1995 |
| 2886 | McGoldrick & Watson DRLG., Co. | | Oil & Gas Operator | Jul 1987 |
| 2887 | McGoldrick & Watson, Et Al | | Oil Operator | Jul 1987 |
| 2888 | McGoldrick & Watson-Walker | | Oil Operator | Jul 1987 |
| 2889 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 2890 | McGowan Working Partners | Jackson, MS 39296 | Oil & Gas Operator | Dec 2000 |
| 2891 | McGowan Working Partners, Inc. | Jackson, MS 39296 | Oil & Gas Operator | May 2026 |
| 2892 | McGowen Resources Co., Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2003 |
| 2893 | McIlhenny-Powell Operating Co | | Gas Operator | Aug 1983 |
| 2894 | McIntyre Oil Company | | Oil & Gas Operator | Jan 1992 |
| 2895 | McKenzie Management Inc. | | Oil & Gas Operator | Aug 1989 |
| 2896 | McKenzie Petroleum Company | Houston, TX 77063 | Oil & Gas Operator | Aug 1995 |
| 2897 | McKenzie Production Company | Houston, TX 77063 | Oil & Gas Operator | May 1995 |
| 2898 | McLain J. Forman | | Oil & Gas Operator | Mar 1988 |
| 2899 | McLaurin Oil Co. | | Oil Operator | Jan 2025 |
| 2900 | McLeod Gas Gath & Proc Co. L.L.C. | | Oil Operator | Jul 2012 |