| 301 | McBee, Jim Co. | Santa Anna, TX 76878 | Oil & Gas Operator | Mar 2012 |
| 302 | McBrayer Oil Corporation | Rockport, TX 78381 | Oil & Gas Operator | Nov 1994 |
| 303 | McBride Operating LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 304 | McBride Production Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 1993 |
| 305 | McBride, Jerrel L Enterprise Inc | Kilgore, TX 75663 | Oil & Gas Operator | Jun 1999 |
| 306 | McCabe Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2009 |
| 307 | McCamey Oil And Gas LLC | MC Camey, TX 79752 | Oil Operator | Dec 2025 |
| 308 | McCammon Oil & Gas, Inc. | San Angelo, TX 76902 | Oil & Gas Operator | Dec 2025 |
| 309 | McCann Corporation | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 310 | McCarter, A. Nelson | Houston, TX 77063 | Oil & Gas Operator | Aug 2003 |
| 311 | McCarter, W. B. Jr. | Houston, TX 77063 | Oil & Gas Operator | Feb 2002 |
| 312 | McCarthy Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Oct 2007 |
| 313 | McCauley Production | Graham, TX 76450 | Oil Operator | Dec 2025 |
| 314 | McCauley, F. R. | Houston, TX 77002 | Oil & Gas Operator | Apr 2000 |
| 315 | McClelland Creek Properties,Inc. | Pampa, TX 79066 | Oil & Gas Operator | Dec 2025 |
| 316 | McClure Brothers | Denton, TX 76210 | Oil & Gas Operator | Dec 2025 |
| 317 | McClure Oil Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 318 | McClure, J.D. Trust | Denton, TX 76209 | Oil & Gas Operator | Dec 2025 |
| 319 | McClymond, B. W. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2020 |
| 320 | McClymond, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2001 |
| 321 | McClymond, LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2009 |
| 322 | McCombs Energy LLC | Houston, TX 77056 | Oil & Gas Operator | Jan 2006 |
| 323 | McCombs Energy, LTD. | Houston, TX 77056 | Oil & Gas Operator | Aug 2017 |
| 324 | McCommons Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2025 |
| 325 | McCool John E | Youngsville, PA 16371 | Oil & Gas Operator | Sep 2025 |
| 326 | McCormack, Lowell Ray | Gainesville, TX 76240 | Oil & Gas Operator | Dec 1993 |
| 327 | McCormack, Paul H. | Gainesville, TX 76241 | Oil & Gas Operator | Sep 2003 |
| 328 | McCormick Operating, L.L.C. | Olney, TX 76374 | Oil Operator | Sep 2015 |
| 329 | McCormick Production Co, Inc. | Oil City, LA 71061 | Oil & Gas Operator | Dec 2025 |
| 330 | McCown Engineering | Wichita Falls, TX 76310 | Oil & Gas Operator | Dec 2025 |
| 331 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Oct 2025 |
| 332 | McCracken, H. L. Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2025 |
| 333 | McCrary & Franklin, Inc. | Post, TX 79356 | Oil & Gas Operator | May 2012 |
| 334 | McCrary Oil Company, Inc. | College Sta, TX 77840 | Oil & Gas Operator | Sep 2019 |
| 335 | McCrea Exploration Company, Inc. | Carrollton, TX 75007 | Oil & Gas Operator | Nov 1995 |
| 336 | McCullis Resources Co., Inc. | Littleton, CO 80161 | Oil & Gas Operator | Aug 2025 |
| 337 | McCulliss Resources Co Inc | Littleton, CO 80161-3248 | Oil & Gas Operator | Jun 2009 |
| 338 | McCurdy Energy LLC | Midland, TX 79707 | Oil Operator | Dec 2025 |
| 339 | McCurdy Oil Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2025 |
| 340 | McCutchin Petroleum Corporation | Dallas, TX 75225 | Oil & Gas Operator | Dec 2025 |
| 341 | McCutchin, Gene | Dallas, TX 75380 | Oil & Gas Operator | Aug 2003 |
| 342 | McCutchin, Jerry | Dallas, TX 75380 | Oil & Gas Operator | Mar 2008 |
| 343 | MCD, Inc. | San Angelo, TX 76904 | Oil & Gas Operator | Aug 2003 |
| 344 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Dec 2025 |
| 345 | McDaniel Oil Co. | Marble Falls, TX 78654 | Oil & Gas Operator | Dec 2025 |
| 346 | McDaniel, Willard | Iraan, TX 79744 | Oil & Gas Operator | Nov 2004 |
| 347 | McDaniel, Willard Jr. Oil Co. | Marble Falls, TX 78654 | Oil & Gas Operator | Mar 2005 |
| 348 | McDay Energy Corp. | Dallas, TX 75206 | Oil & Gas Operator | Dec 2025 |
| 349 | McDonald & Johnson Resources,LLC | Cypress, TX 77429 | Oil & Gas Operator | Dec 2010 |
| 350 | McDonald & Pomeroy Operating Co. | Pasadena, TX 77506 | Oil & Gas Operator | Aug 2003 |
| 351 | McDonald Energy, Inc. | Granbury, TX 76049 | Oil & Gas Operator | Dec 2025 |
| 352 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 353 | McDonald Production, LLC | Lubbock, TX 79408 | Oil Operator | Dec 2025 |
| 354 | McDonald Resources, LLC | Jefferson, TX 75657 | Oil & Gas Operator | Dec 2025 |
| 355 | McDonald, Joe | Burkburnett, TX 76354 | Oil & Gas Operator | Aug 1995 |
| 356 | McDonald, R. A. Oil Co. | Borger, TX 79008 | Oil & Gas Operator | Oct 2002 |
| 357 | McDonald, Richard A. | Fredericksbrg, TX 78624 | Oil & Gas Operator | Dec 2025 |
| 358 | McDonnold Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 359 | McDowell Ranch | Shamrock, TX 79079 | Gas Operator | Dec 2025 |
| 360 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 361 | McEuen, Billy Oil Co. | Bowie, TX 76230 | Oil & Gas Operator | Dec 2016 |
| 362 | McEver Oil Company Inc. | Austin, TX 78789 | Oil & Gas Operator | Mar 2008 |
| 363 | McFadden Energy TX, LLC | Lakewood, NY 14750 | Oil Operator | Dec 2025 |
| 364 | McFarland & Scobey, Inc. | El Paso, TX 79947 | Oil & Gas Operator | Dec 2025 |
| 365 | McFarland Energy, Inc. | New Orleans, LA 70160 | Oil & Gas Operator | Dec 2009 |
| 366 | MCG Oil & Gas Operating, LLC | Archer City, TX 76351 | Oil & Gas Operator | Sep 2023 |
| 367 | McGee Drilling Corporation | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 368 | McGee, Tom Corporation | Booker, TX 79005 | Oil & Gas Operator | Aug 2025 |
| 369 | McGehee, George T. Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Oct 1997 |
| 370 | McGhee Exploration And Prod. Co. | Houston, TX 77019 | Oil & Gas Operator | Feb 2003 |
| 371 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 372 | McGowan Working Partners | Jackson, MS 39296 | Oil & Gas Operator | Dec 2000 |
| 373 | McGowan Working Partners, Inc. | Jackson, MS 39296 | Oil & Gas Operator | Dec 2025 |
| 374 | McGowen Resources Co., Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2003 |
| 375 | McGuffin, Joe Jr. | Christoval, TX 76935 | Oil & Gas Operator | Dec 2025 |
| 376 | McGuffin, Joe S. Inc. | Mathis, TX 78368 | Gas Operator | Dec 2025 |
| 377 | McGuire Brothers | Phoenix, AZ 85045 | Oil & Gas Operator | Dec 2025 |
| 378 | McIver, Inc | San Angelo, TX 76903 | Oil & Gas Operator | Dec 2025 |
| 379 | McIver, Terry L. | Santa Anna, TX 76878 | Oil & Gas Operator | Aug 2003 |
| 380 | McKay Oil | Portales, NM 88130 | Oil & Gas Operator | Apr 1996 |
| 381 | McKay Operating LLC | Lubbock, TX 79416 | Oil & Gas Operator | Oct 2023 |
| 382 | McKee, Kenneth W. Oil Co. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 383 | McKeever, Tyra, Swenson Venture | Stamford, TX 79553 | Oil & Gas Operator | Apr 1996 |
| 384 | McKenney & Chambers Oil Company | Westbrook, TX 79565 | Oil & Gas Operator | Oct 2003 |
| 385 | McKenzie Operating Company, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 386 | McKenzie Production Company | Houston, TX 77063 | Oil & Gas Operator | May 1995 |
| 387 | McKinney Operating Company | Canadian, TX 79014 | Gas Operator | May 2002 |
| 388 | McKinney, M. H. | Midland, TX 79701 | Oil & Gas Operator | Apr 1995 |
| 389 | McKnight, C. L. | McLeod, TX 75565 | Oil & Gas Operator | Dec 2025 |
| 390 | McKnight, C. L. Oil Co. LLP | McLeod, TX 75565 | Oil & Gas Operator | Dec 2025 |
| 391 | McKnight, J. C. | Jefferson, TX 75657 | Oil & Gas Operator | Nov 2019 |
| 392 | McLain Exploration, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Mar 2008 |
| 393 | McLelland Engineering & MGMT. | Houston, TX 77042 | Oil & Gas Operator | Mar 1999 |
| 394 | McLemore, Laurence | Iowa Park, TX 76367 | Oil & Gas Operator | Dec 2025 |
| 395 | McLeod, George L. Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2002 |
| 396 | MCM Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 397 | McMahon Operating Co., L.C. | Pampa, TX 79066 | Oil & Gas Operator | Dec 2004 |
| 398 | McMahon-Bullington Drilling Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 1996 |
| 399 | McMahon-Bullington LP | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2009 |
| 400 | McMinn Operating Company, Inc. | Hempstead, TX 77445 | Oil & Gas Operator | Dec 2025 |