| 301 | Midway Terrel Operating Co | | Oil & Gas Operator | Dec 1999 |
| 302 | Miller Brothers | | Oil & Gas Operator | Nov 2000 |
| 303 | Miller Brothers And Federal Oil Co | | Oil Operator | May 1984 |
| 304 | Miller Brothers And Total Petroleum And Wiser Oil | | Oil & Gas Operator | Sep 1991 |
| 305 | Miller Energy Company II LLC | | Oil & Gas Operator | Aug 2025 |
| 306 | Miller Exploration Company | Tulsa, OK 74136-1020 | Oil & Gas Operator | Mar 2015 |
| 307 | Miller Raymond V | | Oil Operator | Jul 2007 |
| 308 | Mills Glen A | | Gas Operator | Dec 1985 |
| 309 | Miracle Petroleum LLC | | Oil & Gas Operator | Oct 2018 |
| 310 | Missaukee Oil And Gas Company LLC | | Oil & Gas Operator | Jun 2025 |
| 311 | Monroe James | | Oil & Gas Operator | Oct 1997 |
| 312 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 313 | Moskowitz Charles J | | Oil Operator | Feb 2014 |
| 314 | Moskowitz Oil & Gas LLC | | Oil Operator | Jul 2025 |
| 315 | Mosthaf Edwin C And Mosthaf Levina M | | Oil Operator | Jul 2020 |
| 316 | Muskegon Development Co And Miller Energy Inc An | | Gas Operator | Dec 1997 |
| 317 | Muskegon Development Company | MT Pleasant, MI 48858 | Oil & Gas Operator | Oct 2025 |
| 318 | Muskegon Operating Company LLC | | Oil & Gas Operator | Aug 2025 |
| 319 | Mutch Harry L | | Oil & Gas Operator | Oct 1991 |
| 320 | Mutch J O | | Gas Operator | Mar 1990 |
| 321 | Mutch Oil And Gas Development Inc | | Oil & Gas Operator | Dec 2004 |
| 322 | Muzyl Oil Corp | | Oil & Gas Operator | Aug 2025 |
| 323 | My Investments Too LLC | | Oil Operator | Jun 2025 |
| 324 | Nagy Joseph | | Oil Operator | Dec 2014 |
| 325 | Nelson Ralph M Enterprises Inc | | Oil Operator | Aug 2025 |
| 326 | Newstar Energy USA Inc | Thornville, OH 43076 | Oil & Gas Operator | Aug 2004 |
| 327 | Neyer Oil Inc | | Oil & Gas Operator | Nov 1997 |
| 328 | Neymeiyer John Oil Co | | Oil Operator | Dec 1998 |
| 329 | North American Exploration Co. | Abilene, TX 79602 | Oil & Gas Operator | Apr 1998 |
| 330 | Northeastern Energy Corp | | Oil & Gas Operator | Dec 2015 |
| 331 | Northern Michigan Oil & Gas Corporation | | Oil & Gas Operator | Aug 2025 |
| 332 | Northern Processors Inc | The Woodlands, TX 77387-9385 | Oil & Gas Operator | Sep 2010 |
| 333 | Northshore Petroleum LLC | | Oil Operator | Feb 2009 |
| 334 | Northstar Energy LLC | | Gas Operator | Sep 2020 |
| 335 | Northwestern Natural Gas | | Gas Operator | Aug 2000 |
| 336 | Nuenergy LLC | | Oil & Gas Operator | Jul 2025 |
| 337 | O I L Energy Corp | | Oil & Gas Operator | Oct 2017 |
| 338 | O I L Niagaran LLC | | Oil & Gas Operator | May 2017 |
| 339 | Okemah Production Inc | | Oil Operator | Dec 2005 |
| 340 | Omega Operating, Inc. | Odessa, TX 79769 | Oil & Gas Operator | Mar 2001 |
| 341 | Omega Resources Inc | | Oil & Gas Operator | Nov 1998 |
| 342 | Omimex Energy, Inc. | Fort Worth, TX 76120 | Oil & Gas Operator | Jun 2025 |
| 343 | Omni Petroleum Corporation | Austin, TX 78738 | Oil & Gas Operator | Oct 2025 |
| 344 | Onco Petroleum USA Inc | | Oil Operator | Dec 2009 |
| 345 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 346 | Ososki Edward D Dba Federal Oil Company | | Oil & Gas Operator | Jun 2025 |
| 347 | Page Lew Barron | | Oil Operator | Dec 2024 |
| 348 | Pan American Petroleum Corp | | Oil & Gas Operator | Jan 2008 |
| 349 | Pangborn Tom Dba Pangborn Exploration | | Oil & Gas Operator | Jan 1993 |
| 350 | Paragon Oil Co | | Oil & Gas Operator | Oct 1991 |
| 351 | Pasadena Oil And Gas Corp | | Oil & Gas Operator | Dec 2001 |
| 352 | Patrick Exploration Company | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2011 |
| 353 | Patrick Petroleum Corp Of Michigan | | Oil & Gas Operator | Nov 1993 |
| 354 | Pats Rent All | | Oil Operator | Jul 2002 |
| 355 | Paxton Resources LLC | | Oil & Gas Operator | Aug 2025 |
| 356 | Peninsular Oil & Gas Co | Ada, MI 49301 | Oil & Gas Operator | Dec 2001 |
| 357 | Perry C A And Son Inc | | Oil & Gas Operator | Dec 1994 |
| 358 | Petco Petroleum Corp | Hinsdale, IL 60521 | Oil & Gas Operator | Jun 2025 |
| 359 | Petro Hunt Inc Of Kentucky | | Oil & Gas Operator | Dec 2006 |
| 360 | Petro Vest Operating LLC | | Oil Operator | Aug 2013 |
| 361 | Petroleum Development Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 362 | Petromax Oil And Gas Inc | | Oil & Gas Operator | Dec 1988 |
| 363 | Phillips Exploration Inc | Warrendale, PA 15086 | Oil & Gas Operator | Dec 2012 |
| 364 | Presidio Exploration, Inc. | Englewood, CO 80155 | Oil & Gas Operator | May 1999 |
| 365 | Presidium Energy LC | | Oil & Gas Operator | Jul 2016 |
| 366 | Preston Oil Co | Woodlands, TX 77380 | Oil & Gas Operator | Dec 2009 |
| 367 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2025 |
| 368 | Prize Petroleum, LLC | Houston, TX 77042 | Oil & Gas Operator | Jun 2012 |
| 369 | Pure Oil Co | | Oil & Gas Operator | Dec 1996 |
| 370 | Putnam Energy LLC | | Oil Operator | Sep 2014 |
| 371 | Quality Hospitality Services LLC | | Oil & Gas Operator | Mar 2013 |
| 372 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Jun 2025 |
| 373 | Quicksilver Resources Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 374 | R And B Energy Co LLC | | Oil Operator | Dec 2011 |
| 375 | R Cubed L L C | | Oil & Gas Operator | Dec 2023 |
| 376 | R S E C LLC | | Oil & Gas Operator | Nov 2002 |
| 377 | Rainbow Oil And Gas Inc | | Oil & Gas Operator | Jun 2016 |
| 378 | Rampart Energy Company | | Oil & Gas Operator | Dec 2024 |
| 379 | Ranch Production Co | | Oil & Gas Operator | Jul 2000 |
| 380 | Ranch Production LLC | | Oil & Gas Operator | Jul 2025 |
| 381 | Range Michigan LLC | | Oil Operator | Dec 2020 |
| 382 | Range Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2000 |
| 383 | Range Resources Appalachia LLC | Canonsburg, PA 15317 | Oil & Gas Operator | Jun 2025 |
| 384 | Rayburn Oil Co Inc | | Oil & Gas Operator | Dec 2024 |
| 385 | Reef Petroleum Corp | | Oil & Gas Operator | Feb 1994 |
| 386 | Reefworks LLC | | Oil & Gas Operator | Aug 2025 |
| 387 | Reservoir Research Corp | | Oil Operator | Dec 2009 |
| 388 | Richter Ervin E | | Oil & Gas Operator | Dec 2009 |
| 389 | Riley Leo M Co | | Gas Operator | Oct 1998 |
| 390 | Riverside Energy Michigan LLC | | Oil & Gas Operator | Jul 2025 |
| 391 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 392 | Rosekrans Janet A Dba J Oil Co | | Oil & Gas Operator | Jan 2003 |
| 393 | Rovsek Adolph E | | Oil & Gas Operator | Oct 1991 |
| 394 | S And M Liquid Tire Fill Inc | | Oil & Gas Operator | Aug 2025 |
| 395 | S R W Inc | | Gas Operator | Aug 2017 |
| 396 | Saba Energy Of Texas Inc | Houston, TX 77042 | Oil & Gas Operator | Jul 2007 |
| 397 | Salem Oil LLC | | Oil Operator | Jul 2025 |
| 398 | Samson Natural Gas Co | | Oil & Gas Operator | Oct 1992 |
| 399 | Samson Natural Gas Co And Miller Energy Miller Oil | | Oil & Gas Operator | Aug 2000 |
| 400 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |