| 1 | 3-T Exploration, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2021 |
| 2 | A & W Drilling Co. | | Oil Operator | Sep 1985 |
| 3 | A.D.A. Oil Co | Iowa Park, TX 76367 | Oil Operator | Aug 2003 |
| 4 | Achilles Oil, LLC | | Oil & Gas Operator | Jan 2021 |
| 5 | Ada Oil Exploration Corp | | Oil & Gas Operator | Feb 1986 |
| 6 | Adams Resources Expl. Corp. | Houston, TX 77001 | Oil & Gas Operator | Jan 2018 |
| 7 | Adco Producing Co. | | Oil & Gas Operator | Mar 1989 |
| 8 | Aegis Operating Co., Inc. | | Oil & Gas Operator | Feb 2021 |
| 9 | Ainsworth, Otis | | Oil & Gas Operator | Jun 1987 |
| 10 | Alamosa Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2021 |
| 11 | Albert E. Smith Oil | | Oil Operator | Feb 2021 |
| 12 | Albert M. Stall | | Oil Operator | Dec 1990 |
| 13 | Aldridge Operating Co., LLC | | Oil & Gas Operator | Mar 2019 |
| 14 | Alex Oil Co. | | Oil Operator | Jun 1996 |
| 15 | Allen Operating Company, LLC | | Oil & Gas Operator | Jan 2021 |
| 16 | Allen Petroleum Services Inc. | | Gas Operator | Aug 2000 |
| 17 | Allstar Oil And Gas Inc. | | Oil & Gas Operator | Nov 1992 |
| 18 | Alpine Gas Operator, LLC | | Oil & Gas Operator | Feb 2021 |
| 19 | Alpine Well Service, Inc. | | Oil & Gas Operator | Feb 2021 |
| 20 | Amax Petroluem Corp. | | Oil & Gas Operator | Nov 1983 |
| 21 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Feb 2016 |
| 22 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 23 | American Quasar Petroleum Co. | Midland, TX 79705 | Oil & Gas Operator | Jun 1987 |
| 24 | American Southwest Corp. | | Oil & Gas Operator | Dec 1989 |
| 25 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 26 | Amwar Expl. & Allen Petroleum | | Oil & Gas Operator | Jan 2021 |
| 27 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jan 2021 |
| 28 | Anderman/Smith Operating Company | Tulsa, OK 74136 | Oil & Gas Operator | Jan 1999 |
| 29 | Anderson Oil Company | Burkburnett, TX 76354 | Oil & Gas Operator | Oct 2015 |
| 30 | Anderson Operating, LLC | | Oil & Gas Operator | Feb 2021 |
| 31 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Sep 2017 |
| 32 | Apache Corporation | Houston, TX 77056 | Oil & Gas Operator | Apr 2021 |
| 33 | Arkla Exploration Co. | Shreveport, LA 71151 | Oil & Gas Operator | Sep 2006 |
| 34 | Atmos Energy Corp | Dallas, TX 75240 | Oil & Gas Operator | May 1993 |
| 35 | Austin Production Company, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Apr 2009 |
| 36 | Australis TMS Inc. | | Oil & Gas Operator | Feb 2021 |
| 37 | Avad Operating, LLC | Dallas, TX 75201 | Oil & Gas Operator | Apr 2021 |
| 38 | Aviara Energy Corporation | Dallas, TX 75201 | Oil & Gas Operator | May 2013 |
| 39 | B & B Oil Well Service Company, Inc | | Oil Operator | Aug 1988 |
| 40 | B & M Resources, Inc. | | Oil Operator | Apr 1997 |
| 41 | B & W Exploration, Inc. | | Oil & Gas Operator | Dec 2000 |
| 42 | B. H. T. Production, LLC | | Oil & Gas Operator | Apr 2010 |
| 43 | Bailey Equip. | | Oil & Gas Operator | Aug 1983 |
| 44 | Bailey, S. H. | | Oil & Gas Operator | Jul 1995 |
| 45 | Baker Pistol Ridge General Partnership | | Oil & Gas Operator | May 2015 |
| 46 | Bar Production, LLC. | | Oil & Gas Operator | Feb 2021 |
| 47 | Barnhart Co. | Houston, TX 77056 | Oil & Gas Operator | Apr 2021 |
| 48 | Barton Oil, LLC | | Oil & Gas Operator | Jan 2014 |
| 49 | Bass Enterprises Production Co | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2012 |
| 50 | Bean Resources, Inc | | Oil & Gas Operator | Feb 2021 |
| 51 | Beard Oil Company | Oklahoma City, OK 73102 | Oil & Gas Operator | Aug 2015 |
| 52 | Belden & Blake | | Oil & Gas Operator | Feb 1988 |
| 53 | Belle Oil, Inc. | | Oil & Gas Operator | Feb 2021 |
| 54 | Betsy Production Company, Inc. | Magnolia, AR 71753 | Oil & Gas Operator | Feb 2021 |
| 55 | Big Run Production Company | Tyler, TX 75701 | Oil & Gas Operator | Apr 2021 |
| 56 | Big-Joe Operating, Co. | | Oil & Gas Operator | Aug 2018 |
| 57 | Biglane Operating Company | | Oil & Gas Operator | Feb 2021 |
| 58 | Billups Brothers Et Al | | Oil & Gas Operator | Dec 1981 |
| 59 | Black Gold Prod Co., Inc. | | Oil & Gas Operator | Feb 1998 |
| 60 | Black Horse Resources, LLC | | Oil & Gas Operator | Feb 2021 |
| 61 | Black Jack Oil Co Inc | Holliday, TX 76366 | Oil & Gas Operator | Jan 2021 |
| 62 | Blackburn Operating Co., Inc. | | Oil & Gas Operator | Jun 2008 |
| 63 | Block "T" Petroleum, Inc. | Tyler, TX 75710 | Oil & Gas Operator | Apr 2021 |
| 64 | Blue Valley Petroleum, LTD. | | Oil Operator | Jun 1991 |
| 65 | Bluff City Pipe & Supply Co. | | Oil Operator | Jan 1987 |
| 66 | Bob Bertolet | | Oil & Gas Operator | Feb 2021 |
| 67 | Bob Bertolet Et Al | | Oil Operator | Jan 1993 |
| 68 | Bogue Homa Oil Production LLC | | Oil & Gas Operator | Feb 2021 |
| 69 | BPS Operating Services LLC | | Oil Operator | Jan 2005 |
| 70 | Brammer Engineering, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2021 |
| 71 | Breland, Leon | | Oil & Gas Operator | Feb 1991 |
| 72 | Briggs Operating Co | | Oil & Gas Operator | Nov 1998 |
| 73 | Brighton Energy, L.L.C. | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2009 |
| 74 | Bristol Resources Co. | | Oil & Gas Operator | Aug 1989 |
| 75 | Broadway Energy | | Oil Operator | Apr 1983 |
| 76 | Brown, Edward L. | | Oil Operator | Sep 1980 |
| 77 | Browning & Welch, Inc | | Oil & Gas Operator | Mar 2005 |
| 78 | Bruxoil, Inc. | | Oil & Gas Operator | Jan 2021 |
| 79 | Bta Oil Producers, LLC | Midland, TX 79701 | Oil & Gas Operator | Apr 2021 |
| 80 | Bulldog Operating Company LLC | Shreveport, LA 71101-3680 | Oil & Gas Operator | Nov 2015 |
| 81 | Burnsed Oil Co., Inc. | | Oil & Gas Operator | Feb 2021 |
| 82 | C.T.R. Oil, Inc | | Oil & Gas Operator | Dec 2018 |
| 83 | Caledonia Energy Partners, LLC | | Oil & Gas Operator | Mar 2007 |
| 84 | Callon Oil Co, Cambell | | Oil & Gas Operator | Oct 1984 |
| 85 | Callon Petroleum Co. | | Oil & Gas Operator | Oct 2002 |
| 86 | Calpine Natural Gas Company L.P. | Houston, TX 77002 | Oil & Gas Operator | Jul 2002 |
| 87 | Calto Oil Co. Et Al | | Oil Operator | Feb 1991 |
| 88 | Calto Operating Company, Inc. | Dallas, TX 75225 | Oil & Gas Operator | May 2004 |
| 89 | Cameron L. Cox Production | | Oil Operator | Jun 1985 |
| 90 | Campbell Co. Et Al | | Oil Operator | Apr 1986 |
| 91 | Camterra Resources, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Apr 2021 |
| 92 | Capstone Resources, Inc. | | Oil & Gas Operator | Feb 1986 |
| 93 | Carbon Exploration, Inc. | | Oil & Gas Operator | Sep 1981 |
| 94 | Cardneaux Inc | | Oil & Gas Operator | Aug 2009 |
| 95 | Carl E. Gungoll Exploration LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2021 |
| 96 | Case Energy, LLC | | Oil & Gas Operator | Feb 2021 |
| 97 | Castor Exploration, Inc. | | Oil & Gas Operator | Dec 1991 |
| 98 | Cavalier Oil Co. Et Al | | Oil Operator | Jan 1986 |
| 99 | Cavins Oilfield Services, LLC. | | Oil Operator | Apr 2006 |
| 100 | CCM Enterprises, Inc | | Oil & Gas Operator | Oct 1985 |