| 1901 | Monroe Well Service-Energy 84 | | Oil Operator | Aug 1989 |
| 1902 | Monroe Well Service-Ged | | Oil Operator | Dec 1988 |
| 1903 | Monroe Well Service-Gotham | | Oil Operator | Apr 1992 |
| 1904 | Monroe Well Service-Gramercy | | Oil Operator | May 1992 |
| 1905 | Monroe Well Service-HGC | | Oil Operator | Dec 1988 |
| 1906 | Monroe Well Service-Lebo | | Oil Operator | Jun 1989 |
| 1907 | Monroe Well Service-Lexington | | Oil Operator | Feb 1989 |
| 1908 | Monroe Well Service-Newtown | | Oil Operator | Aug 1990 |
| 1909 | Monroe Well Service-Ocean | | Oil Operator | Feb 1989 |
| 1910 | Monroe Well Service-Oceanyacht | | Oil Operator | Jan 1989 |
| 1911 | Monroe Well Service-Oil City | | Oil Operator | Aug 1992 |
| 1912 | Monroe Well Service-Omega | | Oil Operator | Aug 1992 |
| 1913 | Monroe Well Service-Par | | Oil Operator | Jan 1990 |
| 1914 | Monroe Well Service-Petrol | | Oil Operator | Sep 1992 |
| 1915 | Monroe Well Service-Petrovest | | Oil Operator | Dec 1988 |
| 1916 | Monroe Well Service-PRG | | Oil Operator | Nov 1990 |
| 1917 | Monroe Well Service-Redstone | | Oil Operator | Jul 1989 |
| 1918 | Monroe Well Service-RVS | | Oil Operator | Dec 1990 |
| 1919 | Monroe Well Service-Shemen | | Oil Operator | Dec 1988 |
| 1920 | Monroe Well Service-Shemen1984 | | Oil Operator | Jan 1989 |
| 1921 | Monroe Well Service-Shemen1985 | | Oil Operator | Nov 1990 |
| 1922 | Monroe Well Service-Sla | | Oil Operator | Mar 1989 |
| 1923 | Monroe Well Service-SPD | | Oil Operator | Dec 1988 |
| 1924 | Monroe Well Service-SPD 1985 | | Oil Operator | Dec 1988 |
| 1925 | Monroe Well Service-TBR | | Oil Operator | Aug 1991 |
| 1926 | Monroe Well Service-TG I | | Oil Operator | Oct 1990 |
| 1927 | Monroe Well Service-TG II | | Oil Operator | Oct 1990 |
| 1928 | Monroe Well Service-TG III | | Oil Operator | Jul 1992 |
| 1929 | Monroe Well Service-TG VI | | Oil Operator | Aug 1989 |
| 1930 | Monroe Well Service-Tpa 1985 | | Oil Operator | Dec 1990 |
| 1931 | Monroe Well Service-Vista | | Oil Operator | Nov 1990 |
| 1932 | Monroe Well Service-West End | | Oil Operator | Dec 1988 |
| 1933 | Monroe Well Service-York | | Oil Operator | Dec 1988 |
| 1934 | Monroe, Cameron | Westfield, NY 14787 | Gas Operator | Dec 2022 |
| 1935 | Monsanto | Englewood, CO 80111 | Oil & Gas Operator | Apr 1986 |
| 1936 | Monsanto Company | Indianapolis, IN 46280 | Oil & Gas Operator | Jan 2005 |
| 1937 | Monsanto Oil Com | | Oil Operator | Nov 1996 |
| 1938 | Monsanto Oil Company | | Oil & Gas Operator | Apr 1986 |
| 1939 | Montalban Oil & Gas Operations, Inc. | Cut Bank, MT 59427 | Oil & Gas Operator | Feb 2024 |
| 1940 | Montana Energy Company, LLC | Houston, TX 77084 | Oil & Gas Operator | Jan 2024 |
| 1941 | Montana Heartland LLC | Bismarck, ND 58504 | Oil & Gas Operator | Jan 2024 |
| 1942 | Montana Land & Exploration, Inc. | Calgary, AB T2P 3E7 | Oil & Gas Operator | Apr 2019 |
| 1943 | Montana Oil Field Acquisition I, LLC | Rutherford, NJ 07070 | Oil Operator | Jun 2016 |
| 1944 | Montana Power Company | Butte, MT 59701 | Oil & Gas Operator | Apr 2002 |
| 1945 | Montana Power Gas Company | | Oil & Gas Operator | Apr 2002 |
| 1946 | Montani Energy, LLC | Smithville, WV 26178 | Gas Operator | Dec 2021 |
| 1947 | Montare Operating, LTD. | Flower Mound, TX 75022 | Oil & Gas Operator | Apr 2024 |
| 1948 | Montclair Energy LLC | | Oil & Gas Operator | Dec 2023 |
| 1949 | Montclair Production Company | Austin, TX 78755 | Oil & Gas Operator | Apr 2024 |
| 1950 | Montco Oil & Gas, Inc. | Pampa, TX 79066 | Oil & Gas Operator | May 1999 |
| 1951 | Monte Grande Exploration, Inc. | Cut Bank, MT 59427 | Oil Operator | Oct 2000 |
| 1952 | Montego Resources Inc | Oklahoma City, OK 73172-0192 | Oil & Gas Operator | Mar 2015 |
| 1953 | Monterey Pipeline Co. | | Oil Operator | Aug 1993 |
| 1954 | Monterey Production Company LLC | | Oil & Gas Operator | Jan 2024 |
| 1955 | Monterey Resources Inc. | | Oil & Gas Operator | Dec 1997 |
| 1956 | Monterey Resources LLC | Dallas, TX 75230 | Oil & Gas Operator | Oct 2019 |
| 1957 | Montex Drilling Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2024 |
| 1958 | Montex Exploration | Sugarland, TX 77478 | Oil Operator | Apr 2003 |
| 1959 | Montex Exploration Company | Houston, TX 77057 | Oil & Gas Operator | Mar 2011 |
| 1960 | Montgomery Count | | Oil Operator | Dec 1992 |
| 1961 | Montgomery Exploration Co LTD | Dallas, TX 75204-2634 | Oil & Gas Operator | Dec 2023 |
| 1962 | Montgomery Jake E | Henryetta, OK 74437 | Oil & Gas Operator | Oct 2023 |
| 1963 | Montgomery Oil & Gas Expl Inc | Tulsa, OK 74170-1884 | Oil & Gas Operator | Mar 2005 |
| 1964 | Montgomery Oil Co | | Oil Operator | Dec 2018 |
| 1965 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 1966 | Montgomery Production & Operating LLC | Herington, KS 67449 | Oil & Gas Operator | Dec 2023 |
| 1967 | Montgomery Royalty | Moran, TX 76464 | Oil & Gas Operator | Apr 2024 |
| 1968 | Monticola Exploration & Production, Inc. | | Gas Operator | Dec 2021 |
| 1969 | Montrose Operating LLC | Broken Arrow, OK 74012 | Oil & Gas Operator | Apr 2024 |
| 1970 | Monty L Hott Production Corporation | Oklahoma City, OK 73142 | Oil & Gas Operator | Dec 2023 |
| 1971 | Monument Gas Marketing Inc | | Oil & Gas Operator | Feb 2024 |
| 1972 | Monument Global Resources Inc | Dallas, TX 75243 | Oil & Gas Operator | Sep 2023 |
| 1973 | Monument Production Inc. | | Oil & Gas Operator | Dec 2011 |
| 1974 | Monument Resources, Inc. | Castle Rock, CO 80104 | Oil & Gas Operator | Jun 2012 |
| 1975 | Moody Energy Co. | Canadian, TX 79014 | Oil & Gas Operator | Dec 2004 |
| 1976 | Moody Oil & Gas Co. | Bridgeport, WV 26330-1051 | Oil & Gas Operator | Dec 2004 |
| 1977 | Moody Oil Co. | Pearsall, TX 78061 | Oil & Gas Operator | Apr 2024 |
| 1978 | Moog Inc. | East Aurora, NY 14052 | Gas Operator | Dec 2022 |
| 1979 | Moon Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Mar 2003 |
| 1980 | Moon-Hines-Tigrett Operating Co., Inc. | | Oil & Gas Operator | Nov 2023 |
| 1981 | Moon-Hines-Tigrett Opr Co Inc | | Oil & Gas Operator | Oct 1995 |
| 1982 | Moonlight Oil And Gas, LLC | | Oil & Gas Operator | Dec 2021 |
| 1983 | Moonlite Oil & Gas Company | Imperial, TX 79743 | Oil & Gas Operator | Apr 2024 |
| 1984 | Moontower Resources Op, LLC | Austin, TX 78732 | Oil & Gas Operator | Apr 2024 |
| 1985 | Moore & Gilmore | Midland, TX 79701 | Oil & Gas Operator | Oct 2008 |
| 1986 | Moore & Moore Energy Inc | Purcell, OK 73080-0674 | Oil & Gas Operator | Dec 2012 |
| 1987 | Moore Clay | Dallas, TX 75218-0217 | Oil & Gas Operator | Dec 2023 |
| 1988 | Moore County Gas Partners, L.P. | Borger, TX 79007 | Gas Operator | Apr 2024 |
| 1989 | Moore David K | Duncan, OK 73575 | Oil & Gas Operator | Oct 2009 |
| 1990 | Moore Don | Elmore City, OK 73433-0012 | Oil & Gas Operator | Dec 2023 |
| 1991 | Moore DRLG LLC | MT Vernon, OH 43050 | Oil Operator | Dec 2023 |
| 1992 | Moore Energy Services, LLC | Iowa Park, TX 76367 | Oil Operator | Apr 2024 |
| 1993 | Moore Gas And Oil | Monahans, TX 79756 | Oil Operator | Apr 2024 |
| 1994 | Moore Investment Co. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 1995 | Moore Investments LC | Oklahoma City, OK 73116-9044 | Oil & Gas Operator | Feb 2023 |
| 1996 | Moore Lynn D | Collinsville, OK 74021 | Oil Operator | Aug 2013 |
| 1997 | Moore McCormack Energy, Inc. | | Oil & Gas Operator | Jul 1988 |
| 1998 | Moore Michael | MT Vernon, OH 43050 | Oil & Gas Operator | Dec 2013 |
| 1999 | Moore Oil & Gas-Marion Corp. | | Oil & Gas Operator | Nov 1986 |
| 2000 | Moore Oil And Gas | Burleson, TX 76028 | Oil & Gas Operator | Apr 2024 |