| 19901 | Mountain States Petroleum Corp | Midland, TX 79702 | Oil & Gas Operator | Apr 2008 |
| 19902 | Mountain States Resources Inc | Cut Bank, MT 59427 | Oil & Gas Operator | Oct 2000 |
| 19903 | Mountain V Oil & Gas, Inc. | Buckhannon, WV 26201 | Oil & Gas Operator | Dec 2021 |
| 19904 | Mountain V, LLC | Buckhannon, WV 26201 | Oil & Gas Operator | Dec 2021 |
| 19905 | Mountain VIew Resources LLC | | Oil & Gas Operator | Apr 2025 |
| 19906 | Mountaineer Gas Transmission, Inc. | Fort Worth, TX 76185-0000 | Oil & Gas Operator | Dec 2021 |
| 19907 | Mountaineer State Energy, Inc. | Dallas, TX 75234 | Oil & Gas Operator | Dec 2021 |
| 19908 | Mountaineer State Operations, LLC | Sandyville, WV 25275 | Oil & Gas Operator | Dec 2024 |
| 19909 | Mountaineer Trading Company, LLC | Charleston, WV 25314 | Oil & Gas Operator | Dec 2016 |
| 19910 | Mourning James & Carol | Middleport, OH 45760-1214-1214 | Gas Operator | Dec 2023 |
| 19911 | Mowata Oil Company | Victoria, TX 77903 | Oil & Gas Operator | Oct 1996 |
| 19912 | Mowdy Robert F | Coalgate, OK 74538 | Oil & Gas Operator | May 2001 |
| 19913 | Moxy Oil Company | Seguin, TX 78155 | Oil & Gas Operator | Aug 2003 |
| 19914 | Moy, Gary | Falls City, TX 78113 | Oil & Gas Operator | Nov 1998 |
| 19915 | Moylan, Jimmie C. | Eastland, TX 76448 | Oil & Gas Operator | Jun 2025 |
| 19916 | Moylan, Thomas F. | Lacygne, KS 66040 | Oil & Gas Operator | Dec 1993 |
| 19917 | Mozark Corporation | Spring, TX 77379-8049 | Oil & Gas Operator | Jan 2011 |
| 19918 | Moze Inc | Ochelata, OK 74051 | Oil & Gas Operator | Jan 2001 |
| 19919 | MPG Petroleum | San Antonio, TX 78217 | Oil & Gas Operator | Aug 2003 |
| 19920 | MPG Petroleum, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jun 2025 |
| 19921 | Mr NM Operating LLC | Dallas, TX 75225 | Oil & Gas Operator | Apr 2025 |
| 19922 | Mr Oil Company | Monahans, TX 79756 | Oil & Gas Operator | Nov 2004 |
| 19923 | MRD Nowata LLC | Woodstock, GA 30189 | Oil Operator | Aug 2017 |
| 19924 | MRD Operating LLC | | Oil & Gas Operator | Dec 2016 |
| 19925 | MRD Operating LLC (Delaware) | Houston, TX 77010 | Oil & Gas Operator | Jul 2015 |
| 19926 | Mri Ventures, Inc. | | Oil Operator | Dec 1993 |
| 19927 | Mroz Baier, Christine | Memphis, TN 38120 | Gas Operator | Dec 2023 |
| 19928 | MRR Oil Inc. | Perryton, TX 79070 | Oil & Gas Operator | Jun 2002 |
| 19929 | Mrs. C. M. Roberson | | Oil Operator | Mar 1989 |
| 19930 | Mrs. Cecile Andries & Sons | | Oil Operator | Dec 2006 |
| 19931 | Mrs. Clara B. Guthrie | | Gas Operator | Jun 1996 |
| 19932 | MRT Exploration Co | | Oil & Gas Operator | Feb 1983 |
| 19933 | MS Producing LLC | Creston, OH 44217 | Oil & Gas Operator | Dec 2024 |
| 19934 | MS United, LLC | | Oil & Gas Operator | Oct 2024 |
| 19935 | MSB Operating | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 2025 |
| 19936 | MSB Operating Company | Enid, OK 73703 | Oil & Gas Operator | Jan 2005 |
| 19937 | MSD Energy, Inc | Rapid City, SD 57702 | Oil & Gas Operator | Dec 2020 |
| 19938 | MSD Operating, LLC | Big Spring, TX 79721 | Oil & Gas Operator | Jun 2025 |
| 19939 | Mse Operating Corp. | Beaverton, OR 97008 | Oil & Gas Operator | Jun 2025 |
| 19940 | MSG Resources Inc. | Iola, KS 66749 | Oil Operator | Feb 2025 |
| 19941 | MSL Oil & Gas Corp | Bradford, PA 16701-0151 | Oil & Gas Operator | Dec 2024 |
| 19942 | MSN Oil, Inc. | Avoca, TX 79503 | Oil Operator | Jun 2025 |
| 19943 | MSR Exploration, Inc. | Winters, TX 79567 | Oil & Gas Operator | Mar 2000 |
| 19944 | MSSK Consulting LLC | San Antonio, TX 78253 | Oil Operator | Jun 2025 |
| 19945 | MT Dora Energy Corporation | Duncan, OK 73533-1829 | Oil & Gas Operator | Apr 2014 |
| 19946 | MT Dora Energy LLC | Houston, OK 77056-1940 | Oil & Gas Operator | Jun 2019 |
| 19947 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Jun 2025 |
| 19948 | MT Savage Refractories | Pittsburgh, PA 15206-0171 | Gas Operator | Dec 2021 |
| 19949 | MT. Crescent Operating Company, LLC | | Oil & Gas Operator | Apr 2025 |
| 19950 | MTBB Acquisition Company, LLC | Houston, TX 77002 | Oil & Gas Operator | Aug 2022 |
| 19951 | MTG Operating Inc | Ridgeland, MS 39158 | Gas Operator | Apr 2011 |
| 19952 | MTM Petroleum, Inc. | Kingman, KS 67068 | Oil & Gas Operator | Feb 2025 |
| 19953 | MTN Energy | Aleppo, PA 15310 | Oil & Gas Operator | Mar 2025 |
| 19954 | MTN V Oil & Gas Inc | Indiana, PA 15701-8914 | Oil & Gas Operator | Dec 2024 |
| 19955 | Mto Oil Company | Okay, OK 74446-0354 | Oil Operator | Jul 2019 |
| 19956 | Mud Creek Operating, LLC | Tyler, TX 75702 | Oil & Gas Operator | Jun 2025 |
| 19957 | Mud Operations Inc | Ames, OK 73718-9501 | Oil & Gas Operator | Apr 2025 |
| 19958 | Mud River Gas Co | | Gas Operator | Dec 2021 |
| 19959 | Mud River Oil & Gas, LLC | Rochester, KY 42273 | Oil Operator | Dec 2023 |
| 19960 | Mudslinger Oil, L.L.C. | Abilene, TX 79601 | Oil Operator | Jun 2025 |
| 19961 | Muegge Don E | Lamont, OK 74643-5010 | Oil & Gas Operator | Dec 1996 |
| 19962 | Muegge, Clay A. | Lamont, OK 74643 | Oil & Gas Operator | Apr 2025 |
| 19963 | Mueggenborg Derrick R Dba DRM Oil & Gas | Yale, OK 74085 | Oil Operator | Apr 2025 |
| 19964 | Mueller Engineering Corp. | Corpus Chrsti, TX 78476 | Oil & Gas Operator | Feb 2002 |
| 19965 | Mueller Exploration, Inc. | Portland, TX 78374 | Oil & Gas Operator | Jun 2025 |
| 19966 | Mueller Fred W | | Oil & Gas Operator | Dec 1995 |
| 19967 | Mueller Oil | | Oil Operator | Feb 2025 |
| 19968 | Mueller Thomas C | Fort Smith, AR 72913 | Gas Operator | Aug 2008 |
| 19969 | Mueller Thomas C LTD | Oklahoma City, OK 73102-5683 | Gas Operator | Aug 2008 |
| 19970 | Muenster Drilling Co. Inc. | Muenster, TX 76252 | Oil & Gas Operator | Jun 2025 |
| 19971 | Muffoletto, Michael R. | Brant, NY 14027 | Gas Operator | Dec 2023 |
| 19972 | Mugg, John D. Jr. | San Antonio, TX 78216 | Oil & Gas Operator | Nov 1997 |
| 19973 | Muirfield Exploration, LTD. | Wichita Falls, TX 76301 | Oil & Gas Operator | Jun 2025 |
| 19974 | Muirfield Resources Company | Tulsa, OK 74101-3166 | Oil & Gas Operator | Jun 2024 |
| 19975 | Muldowney Development, Inc. | Dunkirk, NY 14048 | Gas Operator | Dec 2023 |
| 19976 | Muleshoe Crude, LP | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 19977 | Mull Drilling Company | Wichita, KS 67206 | Oil & Gas Operator | Mar 2025 |
| 19978 | Mullen Exploration Inc | | Oil & Gas Operator | Dec 2002 |
| 19979 | Mullen Resources LLC | Reedy, WV 25270 | Oil & Gas Operator | Dec 2021 |
| 19980 | Mullen William Company | Edmond, OK 73083-1372 | Oil & Gas Operator | May 1999 |
| 19981 | Mullen-Hathorn-Bass | | Oil & Gas Operator | Mar 1985 |
| 19982 | Muller Oil & Gas | Wichita Falls, TX 76307 | Oil & Gas Operator | Jun 2025 |
| 19983 | Mullin, W. B. | Graham, TX 76450 | Oil & Gas Operator | Sep 1998 |
| 19984 | Mullins & Prichard | | Oil & Gas Operator | May 1992 |
| 19985 | Mullins Jimmy R Dba Southcreek Petroleum Co | Dibble, OK 73031 | Oil & Gas Operator | Jan 2021 |
| 19986 | Mullins Well Service | MT Gilead, OH 43338 | Oil & Gas Operator | Dec 2018 |
| 19987 | Mullins, John S | | Oil Operator | Nov 2014 |
| 19988 | Mullins, Manuel | Olney, TX 76374 | Oil & Gas Operator | Jun 2025 |
| 19989 | Mulloy Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 19990 | Mulloy, J. W. Associates, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 2003 |
| 19991 | Multipay Energy, Inc. | Austin, TX 78749 | Oil Operator | Jun 2025 |
| 19992 | Multiplex Resources, Inc. | Baytown, TX 77521 | Oil Operator | Dec 2009 |
| 19993 | Mumford, Catherine | Waterloo, NY 13165 | Gas Operator | Dec 2023 |
| 19994 | Mumford-Gabel, Jennifer And Kyle Gabel | Lawtons, NY 14091 | Gas Operator | Dec 2023 |
| 19995 | Mumma Oil Production Co., Inc. | Allentown, PA 18109-0000 | Oil & Gas Operator | Dec 2019 |
| 19996 | Munday Operating Co., L.L.C. | | Oil & Gas Operator | May 2007 |
| 19997 | Mundell F E | Watertown, SD 57201 | Oil & Gas Operator | Aug 1994 |
| 19998 | Munn, W. H. Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2002 |
| 19999 | Munoco Co. | El Dorado, AR 71730 | Oil & Gas Operator | Jul 2021 |
| 20000 | Munoco Co. L.C. | | Oil & Gas Operator | Jun 2003 |