| 101 | Mastel, Francis E. | Rantoul, KS 66079 | Oil Operator | Oct 2009 |
| 102 | Matador Exploration, Inc. | Sedan, KS 67361 | Oil Operator | Apr 2001 |
| 103 | Matador, Inc. | Sedan, KS 67361 | Oil Operator | Aug 2025 |
| 104 | Matlock, Randall K. | Topeka, KS 66607 | Oil Operator | May 2000 |
| 105 | Mattingly, Inc. | Wichita, KS 67226 | Gas Operator | Jun 2011 |
| 106 | Matuk, Edward C. | Neodesha, KS 66757 | Oil Operator | Aug 1989 |
| 107 | Mauslein, Lenore | Wellsville, KS 66092 | Oil Operator | Oct 2001 |
| 108 | Maverick Oil Co. | Richland, TX 76681 | Oil Operator | Apr 2026 |
| 109 | Max Oil Company | Blackwell, OK 74631 | Oil & Gas Operator | Apr 2024 |
| 110 | Max Oil LLC | Andover, KS 67002 | Oil Operator | Dec 2019 |
| 111 | Max Papay LLC | Meade, KS 67864 | Oil & Gas Operator | Jun 2018 |
| 112 | Maxam Incorporat | | Oil Operator | Jun 1991 |
| 113 | Maxcrude, LLC | Winfield, KS 67156 | Oil & Gas Operator | Dec 2025 |
| 114 | Maxus Exploratio | | Oil Operator | Jun 1991 |
| 115 | Maxwell Operating Co., Inc. | Englewood, CO 80155 | Oil Operator | Jan 2007 |
| 116 | Mayhew Properties | | Gas Operator | Dec 2025 |
| 117 | Mays Oil LLC | | Oil Operator | Apr 2021 |
| 118 | Mays, Sam W., Jr. Estate | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2005 |
| 119 | MB Holdings LLC | Independence, KS 67301 | Oil Operator | Dec 2025 |
| 120 | MBR Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2026 |
| 121 | MC C Oil Co Inc | Sedan, KS 67361 | Oil Operator | Apr 2016 |
| 122 | McCandless Rober | | Oil & Gas Operator | May 1991 |
| 123 | McCann Drilling | | Oil & Gas Operator | Oct 1996 |
| 124 | McCann Drilling, Inc. | Bartlesville, OK 74003 | Oil Operator | Mar 2011 |
| 125 | McCann Mark Wind | | Oil & Gas Operator | Dec 1994 |
| 126 | McCann Petroleum, Inc. | Sedan, KS 67361 | Oil & Gas Operator | Jul 1998 |
| 127 | McCarthy Oil Co. | | Oil Operator | Dec 1998 |
| 128 | McCarthy Oil Com | | Oil Operator | Jun 1994 |
| 129 | McCarthy Tim W - | | Oil Operator | Mar 1994 |
| 130 | McCarty Francis | | Oil Operator | Sep 1993 |
| 131 | McClelland Oil - | | Oil Operator | Dec 2009 |
| 132 | McClelland, C.R. Operations, Inc. | Madison, KS 66860 | Oil Operator | Aug 1998 |
| 133 | McClure M C Oil | | Oil Operator | Jul 1984 |
| 134 | McCluskey Willia | | Oil & Gas Operator | Dec 1990 |
| 135 | McConnell Oil Properties | | Oil Operator | Dec 2025 |
| 136 | McCorgary Operations | | Oil & Gas Operator | Dec 2025 |
| 137 | McCorkle, Frank R. & Kathleen A. | Sedan, KS 67361 | Oil Operator | Oct 2009 |
| 138 | McCoy Petroleum | | Oil & Gas Operator | Aug 1996 |
| 139 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Feb 2026 |
| 140 | McCoy Production | El Dorado, KS 67042 | Oil Operator | Dec 2019 |
| 141 | McCoy, Jon | Erie, KS 66733 | Oil Operator | Dec 2025 |
| 142 | McElvain Energy Inc | Denver, CO 80265 | Oil & Gas Operator | Nov 2019 |
| 143 | McFadden Oil Co. | | Oil Operator | Dec 2025 |
| 144 | McGinness Energy Company Inc | Wichita, KS 67206 | Oil & Gas Operator | Jan 2026 |
| 145 | McGinness Oil Co | Wichita, KS 67202 | Oil & Gas Operator | Dec 2019 |
| 146 | McGinness Oil Company Of Kansas, Inc. | Wichita, KS 67206 | Oil & Gas Operator | Nov 2019 |
| 147 | McGinnis Oil | | Oil & Gas Operator | Dec 2002 |
| 148 | McGown Drilling | | Oil Operator | Apr 1993 |
| 149 | McGown Drilling, Inc. | Mound City, KS 66056 | Oil Operator | Dec 2025 |
| 150 | McGrath, Rollie | Lake City, KS 67071 | Gas Operator | Dec 2025 |
| 151 | McIlvain Oil LLC | Madison, KS 66860 | Oil Operator | Dec 2017 |
| 152 | McKelvy A D Oil | | Gas Operator | Feb 1995 |
| 153 | McLester Oil & G | | Oil & Gas Operator | Jun 1992 |
| 154 | McLouth Operating Company, Inc. | Kansas City, MO 64106 | Oil Operator | Aug 1999 |
| 155 | McMillan, David | FT. Worth, TX 76107 | Oil Operator | Aug 2001 |
| 156 | McMillan, L.L.C. | Sedan, KS 67361 | Oil Operator | Dec 2019 |
| 157 | McMillen, Clay Eugene (Gene) | Chanute, KS 66720 | Oil Operator | Aug 1997 |
| 158 | McMullin Well Se | | Oil & Gas Operator | Sep 1995 |
| 159 | McMullin, Douglas | Wellsville, KS 66092 | Oil Operator | Nov 2025 |
| 160 | McNeish Oil Oper | | Oil & Gas Operator | Feb 1991 |
| 161 | McNeish Oil Operations | | Oil Operator | Nov 2019 |
| 162 | McNic Oil & Gas Midcontinent,Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 1999 |
| 163 | McNown, Carl H. | Moline, KS 67353 | Oil Operator | Jun 2021 |
| 164 | McPherson Drilling | | Oil Operator | Jun 2015 |
| 165 | McPherson Drilling Co. | | Oil Operator | Jan 1998 |
| 166 | McQueeney, John J. | Osawatomie, KS 66064 | Oil Operator | Jan 1985 |
| 167 | McRae, William R. | Scottsdale, AZ 85254 | Oil Operator | Aug 1995 |
| 168 | Mdopps, LLC | Wichita, KS 67203 | Oil Operator | Apr 2023 |
| 169 | Mears, John C. | Chanute, KS 66720 | Oil Operator | Dec 2017 |
| 170 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 171 | Medlen, Dean S. | Rantoul, KS 66079 | Oil Operator | Aug 1993 |
| 172 | Mega Petroleum C | | Oil Operator | Jun 1990 |
| 173 | Meier Joe Oil Op | | Oil Operator | Jul 1983 |
| 174 | Melland Drilling | | Oil Operator | Nov 1992 |
| 175 | Melrose Group In | | Oil Operator | Feb 1994 |
| 176 | Melton, Kenneth | Wann, OK 74083 | Oil Operator | Nov 2025 |
| 177 | Meltzer Oil Comp | | Oil Operator | Dec 1983 |
| 178 | Mem Partnership LP, A General Partnership | Spring, TX 77393 | Oil Operator | Dec 2025 |
| 179 | Mercer Oil And Gas Co Inc | Norman, OK 73070 | Oil & Gas Operator | Apr 2015 |
| 180 | Meredith Enterprises | | Oil Operator | Jun 1988 |
| 181 | Meridian Energy Inc. | | Oil Operator | Dec 2025 |
| 182 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2026 |
| 183 | Merit Energy Company, LLC | Dallas, TX 75009 | Oil & Gas Operator | Dec 2025 |
| 184 | Merrick Oil & Gas | | Oil & Gas Operator | Sep 2025 |
| 185 | Merrico Resource | | Oil Operator | Dec 1996 |
| 186 | Merritt Oil Comp | | Oil Operator | Jan 1990 |
| 187 | Mesa Operating Co. | Irving, TX 75039 | Oil & Gas Operator | Aug 1997 |
| 188 | Mesa Operating L | | Oil & Gas Operator | Dec 1996 |
| 189 | Mesa Petroleum C | | Oil & Gas Operator | Dec 1986 |
| 190 | Messenger Petroleum, Inc. | Kingman, KS 67068 | Oil & Gas Operator | Dec 2025 |
| 191 | Messman Corporation | Wichita, KS 67208 | Oil & Gas Operator | Dec 2025 |
| 192 | Messman-Rinehart | | Oil & Gas Operator | Mar 1991 |
| 193 | Metro Energy Group, Inc. | Bossier City, LA 71112 | Oil & Gas Operator | May 2013 |
| 194 | Metro Energy, Inc. | Gladstone, MO 64118 | Oil Operator | May 1997 |
| 195 | Metro Oil Compan | | Oil Operator | Jan 1991 |
| 196 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | Apr 2026 |
| 197 | Meyer Douglas P | Longmont, CO 80501 | Oil & Gas Operator | Aug 2006 |
| 198 | Meyer, Norbert | Conway Springs, KS 67031 | Oil Operator | Aug 1994 |
| 199 | Meyer, Theodore J. | Conway Springs, KS 67031 | Oil Operator | Dec 2025 |
| 200 | Mica Energy Corp | Lincoln, NE 68516 | Oil & Gas Operator | Dec 2010 |