| 301 | Mendell Petroleum Corporation | Castle Rock, CO 80104-9045 | Oil & Gas Operator | Sep 2004 |
| 302 | Mercer Pet Management Inc | Edmond, OK 73013-6677 | Oil & Gas Operator | Jan 2011 |
| 303 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2024 |
| 304 | Mid-Con Central Expl Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2014 |
| 305 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2024 |
| 306 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 307 | Mito Resources LLC | Edmond, OK 73013 | Oil & Gas Operator | Feb 2024 |
| 308 | Monty L Hott Production Corporation | Oklahoma City, OK 73142 | Oil & Gas Operator | Jan 2024 |
| 309 | Moore & Moore Energy Inc | Purcell, OK 73080-0674 | Oil & Gas Operator | Dec 2012 |
| 310 | Moore Clay | Dallas, TX 75218-0217 | Oil & Gas Operator | Jan 2024 |
| 311 | Moore Richard L | Morris, OK 74445 | Oil Operator | Aug 2013 |
| 312 | Moran-K Oil LLC | Seminole, OK 74818-1295 | Oil & Gas Operator | Feb 2024 |
| 313 | Mott Petroleum Corporation | Sugar Land, TX 77487-3058 | Oil & Gas Operator | Jan 2024 |
| 314 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Apr 2024 |
| 315 | Mud Operations Inc | Ames, OK 73718-9501 | Oil & Gas Operator | Feb 2024 |
| 316 | Muegge, Clay A. | Lamont, OK 74643 | Oil & Gas Operator | Feb 2024 |
| 317 | Mullins Jimmy R Dba Southcreek Petroleum Co | Dibble, OK 73031 | Oil & Gas Operator | Jan 2021 |
| 318 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 319 | National Cooperative RFG Assoc | McPherson, KS 67460-1404 | Oil & Gas Operator | Jun 2006 |
| 320 | National Oil Company | Garden City, KS 67846 | Oil & Gas Operator | Jan 2024 |
| 321 | Nelson Exploration Corporation | | Oil & Gas Operator | Jan 2024 |
| 322 | Nemaha Environmental Services LLC | Enid, OK 73703 | Oil Operator | Feb 2024 |
| 323 | Nielson & Associates Inc | Cody, WY 82414 | Oil & Gas Operator | Feb 2016 |
| 324 | Northwest Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Jun 2014 |
| 325 | O G & E | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Feb 2014 |
| 326 | O'Brien Resources LLC | Shreveport, LA 71136 | Oil Operator | Nov 2017 |
| 327 | Oak Resources Inc | Tulsa, OK 74153 | Oil & Gas Operator | Aug 2013 |
| 328 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 329 | Ofs-Tulsa Corporation | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 1997 |
| 330 | Oklahoma Liquid Resources Inc | Owasso, OK 74055-0841 | Oil & Gas Operator | Jan 2024 |
| 331 | Oklahoma Oil & Gas MGMT Inc | | Oil & Gas Operator | Jan 2024 |
| 332 | Oklahoma Oil Tactics Inc | Edmond, OK 73003-1351 | Oil & Gas Operator | Mar 2015 |
| 333 | Oklahoma Petroleum Allies LLC | Ardmore, OK 73401 | Oil Operator | Oct 2023 |
| 334 | Oklahoma Tank Service Inc | Oklahoma City, OK 73143 | Oil Operator | Aug 1997 |
| 335 | Okland Oil Company | Oklahoma City, OK 73102-9022 | Oil & Gas Operator | Feb 2024 |
| 336 | Okt Petroleum Company Inc | Oklahoma City, OK 73118-7425 | Oil & Gas Operator | Oct 2013 |
| 337 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 338 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 339 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 340 | Onyx Properties Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2006 |
| 341 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Feb 2024 |
| 342 | Oryx Crude Trading & Transporation LP | Dallas, TX 75221 | Oil & Gas Operator | Jun 1999 |
| 343 | Outback Petroleum Inc | Moore, OK 73160-9998 | Oil & Gas Operator | Mar 2015 |
| 344 | Ovation Energy II, LP | Houston, TX 77279 | Oil & Gas Operator | Jun 2011 |
| 345 | Oxford Exploration Company | Denver, CO 80237 | Oil & Gas Operator | Aug 1995 |
| 346 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Apr 2024 |
| 347 | Pacific Enterprise Oil Co USA | Los Angeles, CA 90071-2005 | Oil & Gas Operator | Aug 2012 |
| 348 | Pacific Enterprises Royalty Co | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 349 | Paleo, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Apr 2024 |
| 350 | Paluca Petroleum Inc | Holdenville, OK 74848 | Oil & Gas Operator | Jan 2024 |
| 351 | Panenergy Services Inc | Houston, TX 77525 | Oil & Gas Operator | May 2001 |
| 352 | Panexco Operating LLC | Oklahoma City, OK 73103-2203 | Oil & Gas Operator | Oct 2014 |
| 353 | Paramount Petroleum Corp | Dallas, TX 75374 | Oil Operator | Dec 2000 |
| 354 | Parker & Parsley Dev Co | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 355 | Parker & Parsley Dev LP | Irving, TX 75039-3745 | Oil & Gas Operator | Mar 2015 |
| 356 | Payne W C Family Trust | Oklahoma City, OK 73116-9044 | Oil & Gas Operator | Mar 2015 |
| 357 | PBT Enterprises Inc | Garber, OK 73738-0262 | Oil & Gas Operator | May 2023 |
| 358 | Pegasus Energy Corporation | Oklahoma City, OK 73162 | Oil & Gas Operator | Mar 2015 |
| 359 | Penn VIrginia MC Operating Co LLC | Houston, TX 77084-7213 | Oil & Gas Operator | Feb 2024 |
| 360 | Petro-Hunt Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2003 |
| 361 | Petrocorp Incorporated | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2021 |
| 362 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 363 | Petroleum Production MGMT., Inc. | Kansas City, MO 64112 | Oil & Gas Operator | Apr 2024 |
| 364 | Petroleum Properties MGMT. Co. | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2014 |
| 365 | Petroleum Reserve Corporation | Plymouth MTNG, PA 19462 | Oil & Gas Operator | May 2008 |
| 366 | Pheldon Oil Production Inc | Asher, OK 74826-2629 | Oil & Gas Operator | Feb 2024 |
| 367 | Pioneer Exploration Company | Houston, TX 77090 | Oil & Gas Operator | Feb 2024 |
| 368 | Pioneer Natural Res. USA, Inc. | Irving, TX 75038 | Oil & Gas Operator | Apr 2024 |
| 369 | Plains Liquids Transport Inc | Houston, TX 77002 | Oil & Gas Operator | May 1996 |
| 370 | Plains Marketing LP | Cushing, OK 74023 | Oil & Gas Operator | Dec 2022 |
| 371 | Pogue Randall | Ada, OK 74821-1547 | Oil & Gas Operator | Apr 2014 |
| 372 | Post Petroleum Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Aug 2013 |
| 373 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2024 |
| 374 | Primary Natural Resources III LLC | Tulsa, OK 74136-6351 | Oil & Gas Operator | Feb 2024 |
| 375 | Prime Energy Corp | Charleston, WV 25301-1707-1707 | Oil & Gas Operator | Sep 2015 |
| 376 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Apr 2024 |
| 377 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 378 | Prospective Investment & Trading | Scottsdale, AZ 85261-4190 | Oil & Gas Operator | Jun 2016 |
| 379 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 380 | Proven Reserves Management, Inc. | Dallas, TX 75370 | Oil & Gas Operator | Jan 2024 |
| 381 | Psec Inc | Tulsa, OK 74102-0871 | Oil & Gas Operator | Dec 2016 |
| 382 | Pybas Robert | Wanette, OK 74878 | Oil Operator | Apr 2014 |
| 383 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Jan 2024 |
| 384 | Quest Property Inc | Oklahoma City, OK 73123-3238 | Oil & Gas Operator | Jan 2024 |
| 385 | Questar Energy Trading | Salt Lake City, UT 84145-0601 | Oil & Gas Operator | Mar 2020 |
| 386 | R & H LLC | Ardmore, OK 73401-6329 | Oil & Gas Operator | Mar 2015 |
| 387 | R & N Associates | Grapevine, TX 76051 | Oil & Gas Operator | Jan 2024 |
| 388 | R C Taylor Operating Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2024 |
| 389 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 390 | Ramsey Property MGMT Inc | Oklahoma City, OK 73120-1955 | Oil & Gas Operator | Mar 2019 |
| 391 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 392 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 2024 |
| 393 | Ranken Energy Corporation | Edmond, OK 73013 | Oil & Gas Operator | Jan 2024 |
| 394 | Ratex Resources Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2000 |
| 395 | Raven Resources LLC | Oklahoma City, OK 73172 | Oil & Gas Operator | Jan 2024 |
| 396 | Raw Crude Oil & Gas LLC | Oklahoma City, OK 73104-1801 | Oil & Gas Operator | Feb 2024 |
| 397 | Rawhide Operating, Inc. | New Braunfels, TX 78131 | Oil & Gas Operator | Apr 2024 |
| 398 | Red Hawk Disposal LLC | | Oil Operator | Jun 2023 |
| 399 | Red Rocks Oil & Gas Operating LLC | | Oil & Gas Operator | Feb 2024 |
| 400 | Redtail Investments LLC | Oklahoma City, OK 73179 | Oil & Gas Operator | Feb 2024 |