| 1 | 44 Mag Production Inc | | Gas Operator | Mar 2012 |
| 2 | 4W Ranch | | Oil Operator | Apr 2008 |
| 3 | Aberdeen Petroleum (USA) Inc. | Abilene, TX 79608 | Oil & Gas Operator | Jul 1994 |
| 4 | Abraxas Petroleum Corporation | San Antonio, TX 78258 | Oil & Gas Operator | Apr 2021 |
| 5 | Accidental Oil Company Inc | | Oil & Gas Operator | Dec 2020 |
| 6 | Adobe Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Dec 2000 |
| 7 | Advanced Recovery Services Co | | Oil & Gas Operator | Apr 2007 |
| 8 | Aethon Energy Operating LLC | Dallas, TX 75251 | Oil & Gas Operator | Apr 2021 |
| 9 | Aexco Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Feb 2021 |
| 10 | Agri-Acres Inc | | Oil Operator | Jun 1996 |
| 11 | Ajax Oil Company | Billings, MT 59103 | Oil & Gas Operator | Dec 2003 |
| 12 | Alexander Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Mar 2015 |
| 13 | Allen And Crouch | | Oil & Gas Operator | Mar 2020 |
| 14 | Allen And Schramm Inc | | Oil & Gas Operator | Aug 1996 |
| 15 | Allie Oil | | Oil Operator | May 2000 |
| 16 | Alpha Coal West Inc | | Oil & Gas Operator | Jun 2020 |
| 17 | Alpha Petrovision Us Inc | Canada, 00100 | Oil & Gas Operator | May 2013 |
| 18 | Altex Oil Company | | Oil & Gas Operator | Dec 2005 |
| 19 | Altus Exploration Company | | Oil & Gas Operator | Jul 1984 |
| 20 | Am-West Petroleum Inc | | Oil & Gas Operator | Sep 2015 |
| 21 | Amarex Inc | | Oil & Gas Operator | Dec 1996 |
| 22 | Amax Oil & Gas Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2009 |
| 23 | Amberex Corporation | | Oil & Gas Operator | Sep 1984 |
| 24 | Ambrit Energy Corp. | Garland, TX 75044 | Oil & Gas Operator | May 1999 |
| 25 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Feb 2016 |
| 26 | American Eagle Oil | | Oil & Gas Operator | Dec 2012 |
| 27 | American Energy Partners Inc | Boerne, TX 78006 | Oil & Gas Operator | Dec 2011 |
| 28 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 29 | Ames Oil And Gas | | Oil & Gas Operator | Apr 1986 |
| 30 | Aminoil USA Inc | | Oil & Gas Operator | Dec 1984 |
| 31 | Amplify Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2021 |
| 32 | Ampolex Wy Inc | | Oil & Gas Operator | Mar 1997 |
| 33 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Apr 2021 |
| 34 | Anadarko Minerals, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2021 |
| 35 | Anadarko Ogc Company | Houston, TX 77251 | Oil & Gas Operator | Dec 1998 |
| 36 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jan 2021 |
| 37 | Anchor Bay Corporation | Denver, CO 80202 | Oil & Gas Operator | Jun 2007 |
| 38 | Anderson Management Company | | Oil & Gas Operator | May 2016 |
| 39 | Anderson Oil Company | Burkburnett, TX 76354 | Oil & Gas Operator | Oct 2015 |
| 40 | Andrikopoulos A G | | Oil & Gas Operator | Dec 1994 |
| 41 | Angus Petroleum Corporation | | Oil & Gas Operator | Jan 2021 |
| 42 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Sep 2017 |
| 43 | Anschutz Corporation, The | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 44 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Apr 2021 |
| 45 | Anschutz Oil Company LLC | | Oil & Gas Operator | Sep 2020 |
| 46 | Anschutz Pinedale Corporation | | Oil & Gas Operator | Dec 2015 |
| 47 | Ant Hills Production | | Oil & Gas Operator | Jan 2021 |
| 48 | Antelope Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2021 |
| 49 | Antelope Resources Inc | Billings, MT 59101 | Oil & Gas Operator | May 2017 |
| 50 | Antero Energy LLC | | Gas Operator | Nov 2003 |
| 51 | Antler Energy LLC | | Oil & Gas Operator | Dec 2020 |
| 52 | Apache Corporation | Houston, TX 77056 | Oil & Gas Operator | Apr 2021 |
| 53 | Apc Operating Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Oct 1996 |
| 54 | Apollo 17 Oil And Gas Inc | | Oil Operator | Feb 1988 |
| 55 | Apollo Drilling And Exploration | | Oil & Gas Operator | Oct 1980 |
| 56 | Apx Western Corporation | | Oil & Gas Operator | Sep 1991 |
| 57 | Aquarius Oil And Gas | | Oil & Gas Operator | Sep 2017 |
| 58 | Arabie, Inc. | Austin, TX 78735 | Oil & Gas Operator | Apr 2021 |
| 59 | Arapaho Petroleum Inc | | Oil & Gas Operator | Feb 1992 |
| 60 | Arch Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Feb 1994 |
| 61 | Argent Energy (Us) Holdings Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Dec 2020 |
| 62 | Argentia Operating Company | | Oil Operator | Oct 1991 |
| 63 | Argo Petroleum Corporation | | Oil & Gas Operator | Dec 1989 |
| 64 | Arjay Oil Company | | Oil & Gas Operator | May 2000 |
| 65 | Arkland Producing Co Inc | Midland, TX 79701 | Oil & Gas Operator | Apr 2021 |
| 66 | Arnell Oil Company | | Oil Operator | Feb 2021 |
| 67 | Arrowhead Resources USA LTD | | Oil & Gas Operator | Dec 1992 |
| 68 | Asamera Oil (Us) Inc | Denver, CO 80201 | Oil & Gas Operator | Jul 1985 |
| 69 | Asher Associates Inc | Centennial, CO 80112 | Oil & Gas Operator | Aug 2016 |
| 70 | Ashland Exploration | | Oil & Gas Operator | May 1979 |
| 71 | Atasca Resources, Inc. | Houston, TX 77219 | Oil & Gas Operator | Apr 2021 |
| 72 | Atlantic Oil And Gas Development LLC | | Oil Operator | Jan 2021 |
| 73 | Atlantic Oil Corporation | | Oil & Gas Operator | Dec 1982 |
| 74 | Atlantic Richfield Company | Plano, TX 75094-1744 | Oil & Gas Operator | Nov 2016 |
| 75 | Atomic Oil & Gas LLC | | Oil & Gas Operator | Dec 2012 |
| 76 | Atx Energy Partners LLC | | Oil & Gas Operator | Feb 2021 |
| 77 | Augustus Energy Partners LLC | Billings, MT 59102 | Oil & Gas Operator | Oct 2013 |
| 78 | Avalon Energy Corporation | | Oil & Gas Operator | Jul 1990 |
| 79 | Axem Resources Inc | Denver, CO 80202-4617 | Oil & Gas Operator | Dec 2015 |
| 80 | Axiom Energy LLC | | Oil Operator | Feb 2010 |
| 81 | Aztec Gas And Oil Corporation | Elephant Butte, NM 87935-0370 | Oil & Gas Operator | Mar 2005 |
| 82 | B J Oil Company | Corsicana, TX 75109 | Oil & Gas Operator | Apr 2021 |
| 83 | B3T LLC | | Oil Operator | Jan 2021 |
| 84 | Baldes Henry | | Oil Operator | Dec 1998 |
| 85 | Balidor Oil & Gas LLC | | Oil & Gas Operator | Feb 2021 |
| 86 | Ballard Petroleum Holdings LLC | Billings, MT 59104 | Oil & Gas Operator | Feb 2021 |
| 87 | Balsam R C | | Oil & Gas Operator | Apr 1991 |
| 88 | Bandera Energy Company | | Oil & Gas Operator | Mar 1986 |
| 89 | Banding M R Inc | Gillette, WY 82717 | Oil & Gas Operator | Feb 2021 |
| 90 | Baney Well Service Inc | | Oil Operator | Jun 2016 |
| 91 | Banks And Conrad | | Oil Operator | Sep 1987 |
| 92 | Banks Operating Company | | Oil & Gas Operator | Jul 1989 |
| 93 | Bannon Energy Inc | Houston, TX 77068 | Oil & Gas Operator | Jun 1998 |
| 94 | Banta And Haigh | | Oil & Gas Operator | Feb 1998 |
| 95 | Barbe D F | | Oil & Gas Operator | Dec 2000 |
| 96 | Barrel Springs Development Corp | | Oil & Gas Operator | Oct 1986 |
| 97 | Barrett Patrick | | Oil & Gas Operator | Apr 1988 |
| 98 | Basf Corporation | Houston, TX 77027 | Oil & Gas Operator | Nov 1992 |
| 99 | Basin Resources Corporation | | Oil Operator | May 2013 |
| 100 | Bass Enterprises Production Co | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2012 |