| 301 | Moss Petroleum Company | Dallas, TX 75207 | Oil & Gas Operator | Apr 2026 |
| 302 | Mountain Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Apr 2013 |
| 303 | Moylan, Thomas F. | Lacygne, KS 66040 | Oil & Gas Operator | Dec 1993 |
| 304 | MSG Resources Inc. | Iola, KS 66749 | Oil Operator | Dec 2025 |
| 305 | MTM Petroleum, Inc. | Kingman, KS 67068 | Oil & Gas Operator | Dec 2025 |
| 306 | Muegge, Clay A. | Lamont, OK 74643 | Oil Operator | Aug 1991 |
| 307 | Mueller Oil | | Oil Operator | Dec 2025 |
| 308 | Mull Drilling Company | Wichita, KS 67206 | Oil & Gas Operator | Jan 2026 |
| 309 | Multiplex Resources, Inc. | Baytown, TX 77521 | Oil Operator | Dec 2009 |
| 310 | Murchison Oil & | | Oil Operator | Mar 1988 |
| 311 | Murfin Drilling | | Oil & Gas Operator | Jul 1997 |
| 312 | Murfin Drilling Company, Inc. | Wichita, KS 67202 | Oil & Gas Operator | Feb 2026 |
| 313 | Murjo Oil & Royalty Company | Fort Worth, TX 76121 | Oil & Gas Operator | Dec 2019 |
| 314 | Murk, James M. | Wheaton, IL 60189 | Gas Operator | Jan 1999 |
| 315 | Murphy, Charles H. | Altoona, KS 66710 | Oil Operator | Jul 2022 |
| 316 | Murphy, Earl M. | Madison, KS 66860 | Oil Operator | Jun 1999 |
| 317 | Murray Oil And Gas LLC | Greensburg, KS 67054 | Oil & Gas Operator | Dec 2025 |
| 318 | Musgrove Casey O | | Oil Operator | Oct 1993 |
| 319 | Musgrove Casey Oil | Ponca City, OK 74602-0391 | Oil & Gas Operator | Jun 2017 |
| 320 | Musgrove Energy Inc | Ponca City, OK 74602 | Oil & Gas Operator | Dec 2025 |
| 321 | Musgrove Petrole | | Oil & Gas Operator | Dec 1996 |
| 322 | Musgrove Produci | | Oil Operator | May 1989 |
| 323 | Musgrove Producing | El Dorado, KS 67042 | Oil Operator | Apr 2001 |
| 324 | Mustang Drilling | | Oil & Gas Operator | Nov 1996 |
| 325 | Mustang Drilling, Inc. | Henderson, TX 75653 | Oil & Gas Operator | Aug 2024 |
| 326 | Mustang Energy Corporation | Hays, KS 67601 | Oil Operator | Dec 2025 |
| 327 | Mustang Fuel Cor | | Oil & Gas Operator | Dec 1990 |
| 328 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2026 |
| 329 | Mustang Oil & Gas Corporation | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2021 |
| 330 | MV Purchasing LLC | Wichita, KS 67206 | Oil & Gas Operator | Dec 2019 |
| 331 | MVRC Partnership | Russell, KS 67655 | Oil Operator | Jan 1992 |
| 332 | MW Oil, Inc | | Oil & Gas Operator | Dec 2025 |
| 333 | MWK Petroleum, LLC | Augusta, KS 67010 | Oil Operator | Dec 2025 |
| 334 | Myers Drilling And Exploration Inc. | Sedan, KS 67361 | Oil Operator | Aug 2022 |
| 335 | Myers Robert W J | | Oil Operator | Jun 1991 |
| 336 | Myers, Gus & Annie | Sedan, KS 67361 | Oil Operator | Aug 2017 |