| 1 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | Sep 2025 |
| 2 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Jun 2025 |
| 3 | Mack Oil Company | Duncan, OK 73534 | Oil & Gas Operator | Nov 2000 |
| 4 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | Jun 2025 |
| 5 | Magnum Energy Inc | Norman, OK 73072-2403 | Oil & Gas Operator | Jun 2025 |
| 6 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Jun 2025 |
| 7 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Jul 2025 |
| 8 | Mark A Meier Dba MSC Oil And Gas Co | Oklahoma City, OK 73105 | Oil & Gas Operator | Jun 2025 |
| 9 | Mark L Shidler Inc | Houston, TX 77055 | Oil & Gas Operator | Jun 2025 |
| 10 | Marler Philip | Purcell, OK 73080-1522 | Oil & Gas Operator | Nov 2016 |
| 11 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | May 2025 |
| 12 | Marsh Operating Company | Dallas, TX 75221 | Oil & Gas Operator | Apr 2025 |
| 13 | Matador E & P Company Inc | | Oil & Gas Operator | May 2020 |
| 14 | Maverick Drilling Co., Inc. | Austin, TX 78729 | Oil & Gas Operator | Mar 2015 |
| 15 | Maxine Oil Company | Muskogee, OK 74401-0512 | Oil & Gas Operator | Sep 2014 |
| 16 | Maxwell Resources Corporation | Oklahoma City, OK 73116-7746 | Oil & Gas Operator | Apr 2009 |
| 17 | May Petroleum, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Nov 1998 |
| 18 | MBR Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Sep 2025 |
| 19 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Jul 2025 |
| 20 | McQueen Ed & Company Inc | Lindsey, OK 73052 | Oil & Gas Operator | Apr 2014 |
| 21 | Meade Energy Corporation | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | Jun 2025 |
| 22 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Jun 2025 |
| 23 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 24 | Mep Operating LLC | Houston, TX 77056-2733 | Oil & Gas Operator | May 2025 |
| 25 | Meridian Oil Production Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 2024 |
| 26 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Sep 2025 |
| 27 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 28 | Metropolitan Resources Corp | Tulsa, OK 74169-1734 | Oil & Gas Operator | Mar 2015 |
| 29 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | Sep 2025 |
| 30 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 31 | Midwest Pipe & Supply Company | Oklahoma City, OK 73154-0245 | Oil & Gas Operator | Dec 2008 |
| 32 | Minerva Oil Company | Tulsa, OK 74152-0858 | Oil & Gas Operator | Mar 2015 |
| 33 | Mobil Exp & Prod Us Inc | Houston, TX 77060-1991 | Oil & Gas Operator | May 2001 |
| 34 | Monroe Natural Gas Inc | Norman, OK 73071 | Oil & Gas Operator | May 2025 |
| 35 | Moore & Moore Energy Inc | Purcell, OK 73080-0674 | Oil & Gas Operator | Dec 2012 |
| 36 | Moore Don | Elmore City, OK 73433 | Oil & Gas Operator | May 2025 |
| 37 | Moore Investments LC | Oklahoma City, OK 73116-9044 | Oil & Gas Operator | Feb 2023 |
| 38 | Moore Petroleum Invest Corp | Norman, OK 73072-4217 | Oil & Gas Operator | May 2025 |
| 39 | Moran-K Oil LLC | Seminole, OK 74868 | Oil & Gas Operator | Jun 2025 |
| 40 | Morgan Oil Company | Nacogdoches, TX 75963 | Oil & Gas Operator | May 2006 |
| 41 | Morgan Petroleum Company | Edmond, OK 73083 | Oil & Gas Operator | Mar 1993 |
| 42 | Mott Oil & Gas | Sugarland, TX 77478 | Oil & Gas Operator | May 2001 |
| 43 | Mott Petroleum Corporation | Sugar Land, TX 77487 | Oil & Gas Operator | Aug 2024 |
| 44 | Muegge, Clay A. | Lamont, OK 74643 | Oil & Gas Operator | Jun 2025 |
| 45 | Mullins Jimmy R Dba Southcreek Petroleum Co | Dibble, OK 73031 | Oil & Gas Operator | Jan 2021 |
| 46 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 47 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 48 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |