| 1 | M & M Oil Co., LLC | Oil City, LA 71061 | Oil & Gas Operator | Oct 2025 |
| 2 | M & M Oil Company | Monahans, TX 79756 | Oil & Gas Operator | Jun 2025 |
| 3 | M & M Production | | Oil & Gas Operator | Jun 2010 |
| 4 | M G Gulff | | Oil Operator | May 1988 |
| 5 | M. A. Robison | | Oil & Gas Operator | Oct 1998 |
| 6 | M. E. Fitzgerald | | Oil & Gas Operator | May 1993 |
| 7 | M. F. McCain, Inc. | | Oil & Gas Operator | Jul 1987 |
| 8 | M. P. S. Prod. Co. | Houston, TX 77225 | Oil & Gas Operator | Dec 1996 |
| 9 | M. Parker Production Co. | | Oil Operator | Dec 2024 |
| 10 | M. T. R. Production | | Oil Operator | Mar 2006 |
| 11 | Mako Exploration Management, LLC | Shreveport, LA 71105 | Oil & Gas Operator | Oct 2025 |
| 12 | Mallard Drilling Corp. | | Oil & Gas Operator | Jan 1993 |
| 13 | Malone Oil & Gas Exploration, Inc. | | Oil Operator | Dec 2018 |
| 14 | Mandina & Murphy Oil Company | | Oil Operator | Nov 1990 |
| 15 | Manolo Energy, Inc. | | Oil Operator | Sep 1996 |
| 16 | Manti Exploration Operating LLC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Feb 2015 |
| 17 | Manti Operating Company | Covington, LA 70435 | Oil & Gas Operator | Oct 2025 |
| 18 | Map Associates, L.P. | | Oil & Gas Operator | Mar 1995 |
| 19 | Mar-Bec Energy Company, L.L.C. | Shreveport, LA 71105 | Oil & Gas Operator | May 2001 |
| 20 | Marathon Corporation | | Oil Operator | Dec 1994 |
| 21 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 22 | Marion Corporation | | Oil & Gas Operator | Jan 2001 |
| 23 | Mark Seifer | | Oil & Gas Operator | Dec 2024 |
| 24 | Maroski, Inc. | | Oil Operator | Jan 1989 |
| 25 | Marquis Resources, LLC | | Oil & Gas Operator | Jul 2021 |
| 26 | Marshall & McCain | | Oil & Gas Operator | Oct 1988 |
| 27 | Marshall Exploration, Inc. | | Oil & Gas Operator | Jun 1992 |
| 28 | Martin Oil & Gas Co. | | Oil Operator | Jul 1981 |
| 29 | Martin Production Company | | Oil & Gas Operator | Dec 2024 |
| 30 | Matador Production Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 31 | Matrix Production Company | Sugar Land, TX 77478 | Oil & Gas Operator | Aug 2025 |
| 32 | Maurine B. Pyle | | Oil & Gas Operator | Mar 1993 |
| 33 | Maximus Operating, LTD. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 34 | Maxum Energy Corp | Plano, TX 75025 | Oil & Gas Operator | Jan 2003 |
| 35 | McCormick Production Co, Inc. | Oil City, LA 71061 | Oil & Gas Operator | Oct 2025 |
| 36 | McCurdy Oil Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2025 |
| 37 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 38 | McGowan Working Partners | Jackson, MS 39296 | Oil & Gas Operator | Dec 2000 |
| 39 | McGowan Working Partners, Inc. | Jackson, MS 39296 | Oil & Gas Operator | Oct 2025 |
| 40 | McLaurin Oil Co. | | Oil Operator | Jan 2025 |
| 41 | McLeod Gas Gath & Proc Co. L.L.C. | | Oil Operator | Jul 2012 |
| 42 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 43 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 44 | Metro Energy Group, Inc. | Bossier City, LA 71112 | Oil & Gas Operator | May 2013 |
| 45 | Michael D Brown | | Oil Operator | Jul 1993 |
| 46 | Mid Field Oil Co. | | Oil & Gas Operator | Mar 1989 |
| 47 | Midwest Enterprises, Inc. | Cashion, OK 73016-9626 | Oil & Gas Operator | Apr 2025 |
| 48 | Mike Bonner | | Oil Operator | Aug 1999 |
| 49 | Mobil Oil E & P Southeast Inc | | Oil & Gas Operator | Sep 2013 |
| 50 | Mobley Oil Company, Inc. | | Oil & Gas Operator | Feb 1990 |
| 51 | Mobley Valve Service, Inc. | | Oil & Gas Operator | Nov 2006 |
| 52 | Monroe Well Ser-Amsterdam | | Oil Operator | Dec 1988 |
| 53 | Monroe Well Ser-La Petro II | | Oil Operator | Dec 1988 |
| 54 | Monroe Well Ser-New American85 | | Oil Operator | Dec 1988 |
| 55 | Monroe Well Ser-Ocean Petr '84 | | Oil & Gas Operator | Dec 1988 |
| 56 | Monroe Well Ser-Ocean Yacht II | | Oil Operator | May 1989 |
| 57 | Monroe Well Ser-Oceanyacht1985 | | Oil Operator | Dec 1988 |
| 58 | Monroe Well Ser-Riverside 1985 | | Oil Operator | Dec 1988 |
| 59 | Monroe Well Serv-New American | | Oil Operator | Dec 1988 |
| 60 | Monroe Well Serv-Northern La | | Oil Operator | Dec 1988 |
| 61 | Monroe Well Serv-Omega 1985 | | Oil Operator | Dec 1988 |
| 62 | Monroe Well Service | | Oil & Gas Operator | Apr 1998 |
| 63 | Monroe Well Service-Apk | | Oil Operator | Dec 1988 |
| 64 | Monroe Well Service-Beaver1985 | | Oil Operator | Nov 1991 |
| 65 | Monroe Well Service-Broadway | | Oil Operator | Dec 1988 |
| 66 | Monroe Well Service-Das | | Oil Operator | Mar 1989 |
| 67 | Monroe Well Service-Derrick | | Oil Operator | Dec 1988 |
| 68 | Monroe Well Service-East End | | Oil Operator | Dec 1988 |
| 69 | Monroe Well Service-Empire | | Oil Operator | Dec 1988 |
| 70 | Monroe Well Service-Energy 84 | | Oil Operator | Aug 1989 |
| 71 | Monroe Well Service-Ged | | Oil Operator | Dec 1988 |
| 72 | Monroe Well Service-Gotham | | Oil Operator | Apr 1992 |
| 73 | Monroe Well Service-Gramercy | | Oil Operator | May 1992 |
| 74 | Monroe Well Service-HGC | | Oil Operator | Dec 1988 |
| 75 | Monroe Well Service-Lebo | | Oil Operator | Jun 1989 |
| 76 | Monroe Well Service-Newtown | | Oil Operator | Aug 1990 |
| 77 | Monroe Well Service-Oceanyacht | | Oil Operator | Jan 1989 |
| 78 | Monroe Well Service-Oil City | | Oil Operator | Aug 1992 |
| 79 | Monroe Well Service-Omega | | Oil Operator | Aug 1992 |
| 80 | Monroe Well Service-Par | | Oil Operator | Jan 1990 |
| 81 | Monroe Well Service-Petrol | | Oil Operator | Sep 1992 |
| 82 | Monroe Well Service-Petrovest | | Oil Operator | Dec 1988 |
| 83 | Monroe Well Service-PRG | | Oil Operator | Nov 1990 |
| 84 | Monroe Well Service-Redstone | | Oil Operator | Jul 1989 |
| 85 | Monroe Well Service-RVS | | Oil Operator | Dec 1990 |
| 86 | Monroe Well Service-Shemen1984 | | Oil Operator | Jan 1989 |
| 87 | Monroe Well Service-Shemen1985 | | Oil Operator | Nov 1990 |
| 88 | Monroe Well Service-Sla | | Oil Operator | Mar 1989 |
| 89 | Monroe Well Service-SPD | | Oil Operator | Dec 1988 |
| 90 | Monroe Well Service-SPD 1985 | | Oil Operator | Dec 1988 |
| 91 | Monroe Well Service-TG I | | Oil Operator | Oct 1990 |
| 92 | Monroe Well Service-TG II | | Oil Operator | Oct 1990 |
| 93 | Monroe Well Service-TG III | | Oil Operator | Jul 1992 |
| 94 | Monroe Well Service-TG VI | | Oil Operator | Aug 1989 |
| 95 | Monroe Well Service-Vista | | Oil Operator | Nov 1990 |
| 96 | Monroe Well Service-West End | | Oil Operator | Dec 1988 |
| 97 | Monterey Resources LLC | Dallas, TX 75230 | Oil & Gas Operator | Oct 2019 |
| 98 | Mooringsport Energy Prod Corp | | Oil & Gas Operator | Oct 1994 |
| 99 | Mooringsport Energy Trans Corp | | Oil Operator | Apr 1990 |
| 100 | Moransco Energy Corporation | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |