| 1201 | Mecom Energy Corporation | Houston, TX 77030 | Oil & Gas Operator | Jan 1999 |
| 1202 | Medallion Calif Properties Co. | | Oil & Gas Operator | Dec 2003 |
| 1203 | Medallion Energy Inc | Norman, OK 73072-7436 | Oil & Gas Operator | Aug 2004 |
| 1204 | Medallion Exploration | Holladay, UT 84117 | Oil & Gas Operator | Dec 2015 |
| 1205 | Medallion Exploration Corp. | Midvale, UT 84047 | Oil & Gas Operator | Oct 1998 |
| 1206 | Medallion Oil Company | Houston, TX 77251 | Oil & Gas Operator | Jan 2012 |
| 1207 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 1208 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 1209 | Medders Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2025 |
| 1210 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 1211 | Medina Res Dev Co LLC | Cambridge Springs, PA 16403-3447 | Oil & Gas Operator | Sep 2025 |
| 1212 | Medlen, Dean S. | Rantoul, KS 66079 | Oil Operator | Aug 1993 |
| 1213 | Medora Minerals, LLC | | Oil & Gas Operator | Nov 2025 |
| 1214 | Meeder, Curt N. | Ripley, NY 14775 | Gas Operator | Dec 2024 |
| 1215 | Meehan Doug | Coweta, OK 74429-0813 | Oil & Gas Operator | Apr 2020 |
| 1216 | Meeker & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 1217 | Meeker, Dan Management, Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Aug 2007 |
| 1218 | Meeks, Mike | Tulsa, OK 74136 | Oil Operator | Jan 2025 |
| 1219 | Meerkat Logistics And Operations LLC | Tuscaloosa, AL 35401 | Oil Operator | Oct 2025 |
| 1220 | Mega Drilling Company | | Oil Operator | Feb 1984 |
| 1221 | Mega Energy LLC | Gillette, WY 82718 | Gas Operator | Oct 2025 |
| 1222 | Mega Natural Gas Co | Tulsa, OK 74133 | Oil & Gas Operator | Jul 1996 |
| 1223 | Mega Petroleum C | | Oil Operator | Jun 1990 |
| 1224 | Mega Petroleum Corporation | Dallas, TX 75202 | Gas Operator | Feb 1998 |
| 1225 | Mega Resources Inc | Dallas, TX 75225-0186 | Oil & Gas Operator | Jan 2001 |
| 1226 | Megadon Enterprises, Inc | Salt Lake City, UT 84121 | Oil Operator | May 2020 |
| 1227 | Megaenergy Operating, Inc. | Edmond, OK 73034 | Oil & Gas Operator | Jul 2015 |
| 1228 | Megan Oil & Gas Co., Inc. | Spencer, WV 25276-0000 | Oil & Gas Operator | Dec 2021 |
| 1229 | Megargel Drilling Company | Megargel, TX 76370 | Oil Operator | Nov 1998 |
| 1230 | Megas Corp | North Ridgevill, OH 44039 | Oil & Gas Operator | Dec 1984 |
| 1231 | Megg, L.P. | Borger, TX 79008 | Oil & Gas Operator | Dec 2025 |
| 1232 | Mego Resources, LLC | Taft, TX 78390 | Oil & Gas Operator | Dec 2025 |
| 1233 | Mehaffey Investments, Inc. | Eastland, TX 76448 | Oil & Gas Operator | Dec 2025 |
| 1234 | Mei Operating Company | Lafayette, LA 70598 | Oil & Gas Operator | Aug 1997 |
| 1235 | Meier Joe Oil Op | | Oil Operator | Jul 1983 |
| 1236 | Mel Cox Transports Inc | Comanche, OK 73529-7640 | Oil & Gas Operator | Jul 2022 |
| 1237 | Mel-Ray Oil Company | Nowata, OK 74048-0149 | Oil & Gas Operator | Mar 2004 |
| 1238 | Melanie Oil Dril USA Inc | Millersburg, OH 44654 | Oil & Gas Operator | Dec 1989 |
| 1239 | Melcar Production | Tuscola, TX 79562 | Oil & Gas Operator | Dec 2025 |
| 1240 | Meleen, Catherine M. & Ruch, Jerry E. | Westfield, NY 14787 | Gas Operator | Dec 2024 |
| 1241 | Melland Drilling | | Oil Operator | Nov 1992 |
| 1242 | Mellenco Inc | Scottsdale, AZ 85253 | Oil & Gas Operator | Dec 1990 |
| 1243 | Mello-Dy Resources, LLC | Devine, TX 78016 | Oil Operator | Dec 2025 |
| 1244 | Mellon Creek Operating Co. | Victoria, TX 77901 | Oil & Gas Operator | Jun 1993 |
| 1245 | Mellon Oil Unit | Refugio, TX 78377 | Oil & Gas Operator | Jun 2004 |
| 1246 | Melren Oil & Gas Expl., Inc. | | Gas Operator | Nov 1989 |
| 1247 | Melrose Group In | | Oil Operator | Feb 1994 |
| 1248 | Melrose Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2011 |
| 1249 | Mels Water Service Inc | Lysite, WY 82642 | Oil Operator | Mar 2013 |
| 1250 | Melson Oil & Gas Inc | Broken Arrow, OK 74014 | Oil & Gas Operator | Oct 2025 |
| 1251 | Melton Operating Co. | Friendswood, TX 77546 | Oil & Gas Operator | Jul 2005 |
| 1252 | Melton, Joe, DRLG. Co., Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2004 |
| 1253 | Melton, Kenneth | Wann, OK 74083 | Oil Operator | Sep 2025 |
| 1254 | Meltzer Oil Comp | | Oil Operator | Dec 1983 |
| 1255 | Melvin Or Kathleen Turnbow | Portales, NM 88130 | Oil & Gas Operator | Mar 2006 |
| 1256 | Melzer Exploration Company | Midland, TX 79702-2083 | Oil & Gas Operator | May 2013 |
| 1257 | Mem Partnership LP, A General Partnership | Spring, TX 77393 | Oil Operator | Sep 2025 |
| 1258 | Memaca Petroleum Corporation | | Oil & Gas Operator | Jan 1990 |
| 1259 | Memorial Exploration Company | Saint Louis, MO 63105 | Oil & Gas Operator | Aug 1996 |
| 1260 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 1261 | Menasco, J. | Wichita Falls, TX 76310 | Oil & Gas Operator | Dec 2019 |
| 1262 | Mendell Davis Gas Partners LLC | | Oil & Gas Operator | Dec 2013 |
| 1263 | Mendell Finisterre II LLC | | Oil & Gas Operator | Jun 2017 |
| 1264 | Mendell Petroleum Corporation | Castle Rock, CO 80104-9045 | Oil & Gas Operator | Sep 2004 |
| 1265 | Meng Oper & Expl Co | | Oil & Gas Operator | Dec 1989 |
| 1266 | Meng, Charles H | Lexington, KY 40502 | Gas Operator | Dec 2023 |
| 1267 | Menoah Petroleum Inc | | Oil & Gas Operator | Dec 2024 |
| 1268 | Mentor Energy & Resources | Mentor, OH 44060 | Oil & Gas Operator | Dec 2019 |
| 1269 | Mentren Corporation | | Gas Operator | Nov 2025 |
| 1270 | Mep Operating LLC | Houston, TX 77056-2733 | Oil & Gas Operator | Aug 2025 |
| 1271 | Mer Resources | Edmond, OK 73013 | Oil & Gas Operator | Dec 2025 |
| 1272 | Mer Resources Inc | Edmond, OK 73013-7662 | Oil & Gas Operator | Mar 2015 |
| 1273 | Mer-Bar Exploration Co Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Oct 1992 |
| 1274 | Mercantile Oil & Gas Prod. Corp. | Galena Park, TX 77547 | Oil & Gas Operator | Jun 2016 |
| 1275 | Mercer Oil And Gas Co Inc | Norman, OK 73070 | Oil & Gas Operator | Apr 2015 |
| 1276 | Mercer Pet Management Inc | Edmond, OK 73013-6677 | Oil & Gas Operator | Jan 2011 |
| 1277 | Mercury Exploration Co. | Fort Worth, TX 76104 | Oil & Gas Operator | Dec 2006 |
| 1278 | Mercury Operating, LLC | Dallas, TX 75208 | Oil & Gas Operator | Dec 2025 |
| 1279 | Mercury Petroleum Company, Inc | | Oil Operator | Dec 2018 |
| 1280 | Mercury Resources LLC | | Oil & Gas Operator | Nov 2025 |
| 1281 | Mercy Oil And Gas, LP | Aransas Pass, TX 78335 | Oil & Gas Operator | Dec 2025 |
| 1282 | Meredith Enterprises | | Oil Operator | Jun 1988 |
| 1283 | Mereken Energy Corp. | Fort Worth, TX 76102 | Gas Operator | Feb 2006 |
| 1284 | Merelco Inc | Seminole, OK 74868 | Oil Operator | Jun 2014 |
| 1285 | Merenco | Midland, TX 79702 | Oil & Gas Operator | Dec 1996 |
| 1286 | Merex Resources, Inc. | Amarillo, TX 79159 | Oil & Gas Operator | Sep 2019 |
| 1287 | Meridian Energy Company | Cambridge, OH 43725 | Oil & Gas Operator | Dec 2010 |
| 1288 | Meridian Energy Inc. | | Oil Operator | Sep 2025 |
| 1289 | Meridian Exploration Inc | Oklahoma City, OK 73128 | Oil & Gas Operator | Aug 2013 |
| 1290 | Meridian Exploration Corp. | Pittsburgh, PA 15222 | Oil & Gas Operator | Dec 2021 |
| 1291 | Meridian Interests, Inc. | San Antonio, TX 78239 | Oil & Gas Operator | Aug 2003 |
| 1292 | Meridian Oil & Gas Enter | Blairsville, PA 15717 | Oil & Gas Operator | Dec 2004 |
| 1293 | Meridian Oil & Gas Enterprises Inc | Blairsville, PA 15717-0337 | Oil & Gas Operator | Dec 2003 |
| 1294 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 1295 | Meridian Oil Inc.-Midland | Midland, TX 79702 | Oil & Gas Operator | Jul 1996 |
| 1296 | Meridian Oil Offshore Inc. | | Oil & Gas Operator | Aug 1996 |
| 1297 | Meridian Oil Production Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 2024 |
| 1298 | Meridian Production Services LLC | | Oil & Gas Operator | Dec 2025 |
| 1299 | Meridian Resource & Expl Co, The | Houston, TX 77077 | Oil & Gas Operator | Dec 2000 |
| 1300 | Meridian Resource & Expl LLC,The | Houston, TX 77094 | Oil & Gas Operator | Nov 2012 |