| 18001 | Manzano LLC | Roswell, NM 88202 | Oil & Gas Operator | Oct 2025 |
| 18002 | Manzano Oil Corporation | Roswell, NM 88202 | Oil & Gas Operator | Feb 2005 |
| 18003 | Manziel Interests | Tyler, TX 75711 | Oil & Gas Operator | Jun 2004 |
| 18004 | Manziel Management Corporation | Tyler, TX 75711 | Oil Operator | Feb 2014 |
| 18005 | Map Associates, L.P. | | Oil & Gas Operator | Mar 1995 |
| 18006 | Map Drilling Company | | Oil & Gas Operator | Apr 2012 |
| 18007 | Map Oil Co. | | Oil Operator | Jan 1978 |
| 18008 | Map Production Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 18009 | Mapco Inc | Billings, MT 59102 | Oil & Gas Operator | Dec 1983 |
| 18010 | Mapco Oil & Gas Company | Tulsa, OK 74101-2115 | Oil & Gas Operator | Jan 1985 |
| 18011 | Mapco Oil Company | | Oil & Gas Operator | Jan 1985 |
| 18012 | Mapco Production Co | Billings, MT 59102 | Oil & Gas Operator | Apr 1994 |
| 18013 | Maple Energy Holdings, LLC | Houston, TX 77007 | Oil & Gas Operator | Sep 2023 |
| 18014 | Maple Grove Enterprises Inc | Rimersburg, PA 16248-6415 | Oil & Gas Operator | Dec 2024 |
| 18015 | Maple Gulf Coast Props. Corp. | | Oil & Gas Operator | Jun 1989 |
| 18016 | Maple Lane Farms Dairy And Grain LLC | Marietta, NY 13110 | Gas Operator | Dec 2024 |
| 18017 | Maple Leaf Energ | | Oil & Gas Operator | Sep 1989 |
| 18018 | Maple Properties Corp | Dallas, TX 75204 | Oil & Gas Operator | Jan 1999 |
| 18019 | Mar Oil & Gas Corp. | Santa Fe, NM 87502 | Oil & Gas Operator | Aug 2025 |
| 18020 | Mar Oil Company | Upper Sandusky, OH 43351 | Oil & Gas Operator | Dec 2023 |
| 18021 | Mar-Bar Enterprises Inc | Cushing, OK 74023-3031 | Oil Operator | Jun 2025 |
| 18022 | Mar-Bec Energy Company, L.L.C. | Shreveport, LA 71105 | Oil & Gas Operator | May 2001 |
| 18023 | Mar-Lou Oil Co., LLC | Wilson, KS 67490 | Oil Operator | Jun 2025 |
| 18024 | Mar-Low Corporation | | Oil & Gas Operator | Mar 1992 |
| 18025 | Mar-Win Development Co. | | Oil & Gas Operator | Nov 1988 |
| 18026 | Mar/Reg Investments | Irving, TX 75016 | Oil & Gas Operator | Jul 1999 |
| 18027 | Mar/Reg Oil Company | Reno, NV 89511 | Oil & Gas Operator | Jul 2025 |
| 18028 | Maralex Resources Inc | Ignacio, CO 81137 | Oil & Gas Operator | Aug 2025 |
| 18029 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 18030 | Maralo, LLC | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 18031 | Maram Energy Inc | MT Vernon, OH 43050 | Oil & Gas Operator | Dec 2024 |
| 18032 | Maran Oil Company | San Antonio, TX 78216 | Oil & Gas Operator | Dec 2020 |
| 18033 | Maran Oil Company, LLC | San Antonio, TX 78216 | Oil & Gas Operator | Mar 2022 |
| 18034 | Maranatha Energy Corporation | Athens, WV 24712 | Oil & Gas Operator | Dec 2021 |
| 18035 | Maranatha Exploration Inc | Killbuck, OH 44637 | Oil & Gas Operator | Dec 1992 |
| 18036 | Maranatha Exploration, LP | Wichita Falls, TX 76307 | Oil Operator | Feb 2012 |
| 18037 | Maranatha Oil Company | Gonzales, TX 78629 | Oil & Gas Operator | Oct 2025 |
| 18038 | Maranatha Petroleum Inc. | | Oil & Gas Operator | Jul 2025 |
| 18039 | Marata Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 18040 | Marathon Corporation | | Oil Operator | Dec 1994 |
| 18041 | Marathon Oil Co.-Rocky Mountain Region | Cody, WY 82414 | Oil Operator | Dec 1999 |
| 18042 | Marathon Oil Com | | Oil & Gas Operator | Dec 1996 |
| 18043 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 18044 | Marathon Oil Company LLC | Houston, TX 77079 | Oil & Gas Operator | Jul 2025 |
| 18045 | Marathon Oil Company Operator | | Oil & Gas Operator | Dec 1993 |
| 18046 | Marathon Oil Company/Fina | | Oil & Gas Operator | Jan 2005 |
| 18047 | Marathon Oil Ef LLC | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 18048 | Marathon Oil Permian LLC | Midland, TX 79701 | Oil & Gas Operator | Aug 2025 |
| 18049 | Marben Corporation | | Oil Operator | Jul 1995 |
| 18050 | Marbet LLC | Edmond, OK 73013-6691 | Oil & Gas Operator | Jun 2025 |
| 18051 | Marbil Oil, Inc. | Olney, TX 76374 | Oil & Gas Operator | Jun 2013 |
| 18052 | Marbob Energy Corp | Artesia, NM 882110227 | Oil & Gas Operator | Oct 2010 |
| 18053 | Marchman, J. E. | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 18054 | Marco Drilling Inc | Monroeville, PA 15146-0278 | Oil & Gas Operator | Dec 2024 |
| 18055 | Marco Land & Petroleum, Inc. | | Oil & Gas Operator | Jun 2000 |
| 18056 | Marco Oil Co, Inc | Sparta, KY 41086 | Oil Operator | Dec 2021 |
| 18057 | Marco Oil Compan | | Oil & Gas Operator | Aug 1992 |
| 18058 | Marco Oil Company LLC | Bartlesville, OK 74005 | Oil & Gas Operator | Jun 2025 |
| 18059 | Marco Polo Exploration, Inc. | Rosenberg, TX 77471 | Oil & Gas Operator | Dec 1993 |
| 18060 | Marcon Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2011 |
| 18061 | Marconi Exploration, Inc. | Houston, TX 77056 | Oil & Gas Operator | Aug 1997 |
| 18062 | Marcum Drilling Co. | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 18063 | Marcus Exploration Inc | Piedmont, OK 73078-0308 | Oil & Gas Operator | Dec 2000 |
| 18064 | Mardale Drilling Company | Oklahoma City, OK 73157 | Oil Operator | Nov 1998 |
| 18065 | Marden Petroleum Exp Co | Marietta, OH 45750 | Oil & Gas Operator | Dec 1990 |
| 18066 | Marden Producing | | Gas Operator | Aug 1990 |
| 18067 | Marden Producing Company | Edmond, OK 73083 | Gas Operator | Jun 2025 |
| 18068 | Mare Energy | Danville, OH 43014 | Oil & Gas Operator | Dec 2021 |
| 18069 | Mare Energy LLC | Danville, OH 43014 | Oil & Gas Operator | Dec 2024 |
| 18070 | Marexco | | Oil & Gas Operator | Nov 1994 |
| 18071 | Marexco, Inc. | Castle Rock, CO 80104 | Oil & Gas Operator | Jun 2025 |
| 18072 | Margaret Merganser Inc | Tionesta, PA 16353-5853 | Oil & Gas Operator | Dec 2008 |
| 18073 | Maria L. Andrade | | Oil Operator | Dec 2006 |
| 18074 | Mariah Energy Corp. | Austin, TX 78716 | Oil & Gas Operator | Apr 1999 |
| 18075 | Mariah Exploration LLC | Pawhuska, OK 74056 | Oil & Gas Operator | Oct 2008 |
| 18076 | Mariah Operating Company, LLC | Denver, CO 80201 | Oil & Gas Operator | Dec 2009 |
| 18077 | Marianas Operating Co. | Abilene, TX 79601 | Oil & Gas Operator | Aug 2003 |
| 18078 | Marieff Petroleum, Inc. | Sagamore Hills, OH 44067 | Gas Operator | Dec 2024 |
| 18079 | Marienfeld Exploration | Houston, TX 77005 | Oil & Gas Operator | Mar 1994 |
| 18080 | Marienfeld Exploration, Inc. | Ojai, CA 93024 | Oil & Gas Operator | Oct 2025 |
| 18081 | Marietta Royalty Co Inc | Stillwater, OK 74076 | Oil & Gas Operator | Dec 1986 |
| 18082 | Marina Pacifica Oil Company | | Oil & Gas Operator | Dec 1981 |
| 18083 | Marine Cont. & Supply Inc. | | Oil & Gas Operator | Nov 1985 |
| 18084 | Marine Properties, Inc. | | Oil & Gas Operator | Feb 1995 |
| 18085 | Mariner Energy, Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 18086 | Marino, Charles B. | Tomball, TX 77377 | Oil & Gas Operator | Oct 2025 |
| 18087 | Marion Corporation | | Oil & Gas Operator | Jan 2001 |
| 18088 | Marion County Prod. Co., L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 18089 | Marion Energy Inc | Houston, TX 770082292 | Oil & Gas Operator | May 2015 |
| 18090 | Marion Operating Corp | Marion, OH 43301 | Oil & Gas Operator | Dec 2020 |
| 18091 | Mariposa Petroleum Co. | | Gas Operator | Dec 1980 |
| 18092 | Maritech Resources, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Nov 2009 |
| 18093 | Maritech Resources, LLC | | Oil & Gas Operator | May 2011 |
| 18094 | Marjac Energy Co | Bremen, OH 43107 | Oil & Gas Operator | Dec 1986 |
| 18095 | Marjac Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Oct 2025 |
| 18096 | Marjo Incorporat | | Oil & Gas Operator | Jun 1990 |
| 18097 | Marjo Oil Company | Lockhart, TX 78644 | Oil & Gas Operator | Oct 1999 |
| 18098 | Marjo Operating Company Inc | Tulsa, OK 741010729 | Oil & Gas Operator | Jun 2025 |
| 18099 | Marjo Operating Mid-Continent LLC | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2025 |
| 18100 | Marjo, Inc. | | Oil & Gas Operator | Sep 1991 |