| 101 | Mahler, Kelly Operating | Graham, TX 76450 | Oil & Gas Operator | Mar 2017 |
| 102 | Mai Oil Operations, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Jun 2025 |
| 103 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 104 | Main Street Royalty, Inc. | Lockhart, TX 78644 | Oil & Gas Operator | Aug 1999 |
| 105 | Majestic Oil & Gas Holding Co. | Midland, TX 79705 | Oil Operator | Dec 2025 |
| 106 | Majestic Oil & Gas, Inc. | Pampa, TX 79066 | Oil & Gas Operator | May 2007 |
| 107 | Majestic Petroleum Corporation | Dallas, TX 75230 | Oil & Gas Operator | Oct 1996 |
| 108 | Majestic Resources, Inc. | Dripping SPGS, TX 78620 | Oil & Gas Operator | Nov 2007 |
| 109 | Mak-J Energy Partners(TX),LTD. | Denver, CO 80206 | Oil & Gas Operator | Sep 2013 |
| 110 | Makar Production Company | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 111 | Makk Oil Production Inc. | Monahans, TX 79756 | Oil & Gas Operator | Dec 2025 |
| 112 | Mako Exploration Management, LLC | Shreveport, LA 71105 | Oil & Gas Operator | Dec 2025 |
| 113 | Makoil, Inc. | Lake Forest, CA 92630 | Oil & Gas Operator | Jul 2007 |
| 114 | Maledon Enterprises | Austin, TX 78738 | Oil & Gas Operator | Feb 1996 |
| 115 | Mallon Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2005 |
| 116 | Mallory, Meredith, Jr. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2002 |
| 117 | Malone Oil Production | La Vernia, TX 78121 | Oil & Gas Operator | Dec 2025 |
| 118 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 119 | Mamerow Energy Corp | Ganado, TX 77962 | Oil & Gas Operator | Dec 2025 |
| 120 | Mammoth Exploration LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2023 |
| 121 | Mammoth Operating LLC | Spicewood, TX 78669 | Oil Operator | Dec 2025 |
| 122 | Mandarin Oil & Gas Company | Austin, TX 78714 | Oil & Gas Operator | Dec 2025 |
| 123 | Mandujano, Alfonso & Olga | Von Ormy, TX 78073 | Oil & Gas Operator | Dec 2014 |
| 124 | Mandujano, Alfonso, Jr. | Von Ormy, TX 78073 | Oil Operator | Dec 2025 |
| 125 | Manhattan Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 126 | Manley, John D. III, Oper., Inc | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Feb 2016 |
| 127 | Manning, Jack | Odessa, TX 79760 | Oil & Gas Operator | Dec 2003 |
| 128 | Manti Exploration Operating LLC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Feb 2015 |
| 129 | Manti Operating Company | Covington, LA 70435 | Oil & Gas Operator | Dec 2025 |
| 130 | Manti Tarka Permian Op, LLC | Houston, TX 77056 | Oil & Gas Operator | Dec 2025 |
| 131 | Mantle Oil & Gas, LLC | Friendswood, TX 77546 | Oil & Gas Operator | Dec 2025 |
| 132 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Sep 2025 |
| 133 | Manzanita Corporation | Midland, TX 79710 | Oil & Gas Operator | Nov 2008 |
| 134 | Manzanita Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 135 | Manzano Oil Corporation | Roswell, NM 88202 | Oil & Gas Operator | Feb 2005 |
| 136 | Manzano, LLC | Roswell, NM 88202 | Oil & Gas Operator | Dec 2025 |
| 137 | Manziel Interests | Tyler, TX 75711 | Oil & Gas Operator | Jun 2004 |
| 138 | Manziel Management Corporation | Tyler, TX 75711 | Oil Operator | Feb 2014 |
| 139 | Map Production Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 140 | Maple Energy Holdings, LLC | Houston, TX 77007 | Oil & Gas Operator | Sep 2023 |
| 141 | Mar-Bec Energy Company, L.L.C. | Shreveport, LA 71105 | Oil & Gas Operator | May 2001 |
| 142 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 143 | Maralo, LLC | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 144 | Maran Oil Company | San Antonio, TX 78216 | Oil & Gas Operator | Dec 2020 |
| 145 | Maran Oil Company, LLC | San Antonio, TX 78216 | Oil & Gas Operator | Mar 2022 |
| 146 | Maranatha Exploration, LP | Wichita Falls, TX 76307 | Oil Operator | Feb 2012 |
| 147 | Maranatha Oil Company | Gonzales, TX 78629 | Oil & Gas Operator | Dec 2025 |
| 148 | Marata Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 149 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 150 | Marathon Oil Ef LLC | Houston, TX 77252 | Oil & Gas Operator | Dec 2025 |
| 151 | Marbil Oil, Inc. | Olney, TX 76374 | Oil & Gas Operator | Jun 2013 |
| 152 | Marchman, J. E. | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 153 | Marco Polo Exploration, Inc. | Rosenberg, TX 77471 | Oil & Gas Operator | Dec 1993 |
| 154 | Marcon Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2011 |
| 155 | Marconi Exploration, Inc. | Houston, TX 77056 | Oil & Gas Operator | Aug 1997 |
| 156 | Marcum Drilling Co. | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 157 | Marexco, Inc. | Castle Rock, CO 80104 | Oil & Gas Operator | Jun 2025 |
| 158 | Mariah Energy Corp. | Austin, TX 78716 | Oil & Gas Operator | Apr 1999 |
| 159 | Marianas Operating Co. | Abilene, TX 79601 | Oil & Gas Operator | Aug 2003 |
| 160 | Marienfeld Exploration | Houston, TX 77005 | Oil & Gas Operator | Mar 1994 |
| 161 | Marienfeld Exploration, Inc. | Ojai, CA 93024 | Oil & Gas Operator | Dec 2025 |
| 162 | Mariner Energy, Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 163 | Marino, Charles B. | Tomball, TX 77377 | Oil & Gas Operator | Dec 2025 |
| 164 | Marion County Prod. Co., L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 165 | Maritech Resources, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Nov 2009 |
| 166 | Marjac Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2025 |
| 167 | Marjo Oil Company | Lockhart, TX 78644 | Oil & Gas Operator | Oct 1999 |
| 168 | Marjo Operating Company Inc | Tulsa, OK 741010729 | Oil & Gas Operator | Aug 2025 |
| 169 | Mark I Oil Company | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 170 | Mark IV Energy | San Antonio, TX 78213 | Oil & Gas Operator | Apr 1993 |
| 171 | Mark L Shidler Inc | Houston, TX 77055 | Oil & Gas Operator | Sep 2025 |
| 172 | Mark Oil, Inc. | Chanute, KS 66720 | Oil Operator | Feb 2025 |
| 173 | Markay Oil & Gas Company | Midland, TX 79701 | Oil & Gas Operator | Sep 1998 |
| 174 | Market Street Energy, Inc. | Flatonia, TX 78941 | Oil & Gas Operator | Dec 2025 |
| 175 | Marlin Energy Resources, LLC | Lafayette, LA 70503 | Oil & Gas Operator | May 2018 |
| 176 | Marlin Energy Southwest GP, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Dec 2025 |
| 177 | Marlin Resources, L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Jan 2025 |
| 178 | Marmaton Oil Company | Houston, TX 77002 | Oil & Gas Operator | Jul 1998 |
| 179 | Marmik Oil Company | El Dorado, AR 71730 | Oil & Gas Operator | Jan 2015 |
| 180 | Maroon Energy LLC | Spring, TX 77379 | Oil & Gas Operator | Feb 2025 |
| 181 | Marquee Corporation | Houston, TX 77024 | Oil & Gas Operator | Dec 2025 |
| 182 | Marquise Oil Properties Inc | Konawa, OK 74849 | Oil & Gas Operator | Nov 1992 |
| 183 | Marr, M. H. | Dallas, TX 75201 | Gas Operator | Jan 2002 |
| 184 | Marrow, N. S. | Austin, TX 78703 | Oil & Gas Operator | Aug 2012 |
| 185 | Marsh Operating Company | Dallas, TX 75221 | Oil & Gas Operator | Jun 2025 |
| 186 | Marshall & Winston, Inc. | Midland, TX 79710 | Oil & Gas Operator | Sep 2025 |
| 187 | Marshall Energy, Inc. | Dallas, TX 75243 | Oil & Gas Operator | May 1997 |
| 188 | Marshall Petroleum, Inc. | Houston, TX 77040 | Oil & Gas Operator | Aug 2003 |
| 189 | Marshall Pipe & Supply Co. | Nocona, TX 76255 | Oil & Gas Operator | Mar 2008 |
| 190 | Marshall R. Young Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 191 | Marshall, A. B. | Houston, TX 77050 | Oil & Gas Operator | Sep 1995 |
| 192 | Marshall, Sam | Granbury, TX 76048 | Oil & Gas Operator | Aug 2010 |
| 193 | Marshall, Samuel Meek, Estate Of | Granbury, TX 76048 | Oil & Gas Operator | Dec 2025 |
| 194 | Marshco Production LLC | Colorado City, TX 79512 | Oil Operator | Dec 2025 |
| 195 | Marshfield Oil & Gas, LLC | Houston, TX 77070 | Oil & Gas Operator | Dec 2025 |
| 196 | Martex Oil & Gas, Inc. | Estes Park, CO 80517 | Oil & Gas Operator | Dec 2025 |
| 197 | Martin & Richards Oil Co. | Jacksboro, TX 76458 | Oil & Gas Operator | Jul 1995 |
| 198 | Martin Bros. Oil | Graham, TX 76450 | Oil & Gas Operator | Dec 1993 |
| 199 | Martin Cannon Interests, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 200 | Martin Foree Operating II, LLC | Royse City, TX 75189 | Oil & Gas Operator | Dec 2025 |