| 1 | 4W Ranch | Newcastle, WY 82701 | Oil Operator | Apr 2008 |
| 2 | Aberdeen Petroleum (USA) Inc. | Abilene, TX 79608 | Oil & Gas Operator | Sep 1994 |
| 3 | Abraxas Petroleum Corporation | San Antonio, TX 78258 | Oil & Gas Operator | Mar 2023 |
| 4 | Accidental Oil Company Inc | Newcastle, WY 82701 | Oil & Gas Operator | Feb 2021 |
| 5 | Adams H D LLC | Moorcroft, WY 82721 | Oil & Gas Operator | Feb 2023 |
| 6 | Adobe Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 7 | Advanced Recovery Services Co | Denver, CO 80265 | Oil & Gas Operator | Apr 2007 |
| 8 | Aethon Energy Operating LLC | Dallas, TX 75251 | Oil & Gas Operator | Mar 2023 |
| 9 | Aexco Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Jan 2023 |
| 10 | Agri-Acres Inc | Billings, MT 59103 | Oil Operator | Jun 1996 |
| 11 | Ajax Oil Co | Billings, MT 59103 | Oil & Gas Operator | Dec 2003 |
| 12 | Alexander Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 13 | Allen And Crouch | Casper, WY 82602 | Oil & Gas Operator | Mar 2020 |
| 14 | Allen And Schramm Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 15 | Allie Oil | | Oil Operator | May 2000 |
| 16 | Alpha Coal West Inc | Gillette, WY 82716 | Oil & Gas Operator | Jun 2020 |
| 17 | Alpha Energy, LLC | Ashland, OR 97520 | Oil & Gas Operator | Nov 2022 |
| 18 | Alpha Petrovision Us Inc | Canada, 00100 | Oil & Gas Operator | May 2013 |
| 19 | Altex Oil Company | Breckenridge, CO 80424 | Oil & Gas Operator | Dec 2005 |
| 20 | Altus Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Jul 1984 |
| 21 | Am-West Petroleum Inc | Upton, WY 82730 | Oil & Gas Operator | Sep 2015 |
| 22 | Amarex Inc | | Oil & Gas Operator | Dec 1996 |
| 23 | Amax Oil & Gas Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 24 | Amberex Corporation | Denver, CO 80237 | Oil & Gas Operator | Sep 1984 |
| 25 | Ambrit Energy Corp. | Garland, TX 75044 | Oil & Gas Operator | Jun 2003 |
| 26 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 27 | American Eagle Oil | Casper, WY 82605 | Oil & Gas Operator | Dec 2012 |
| 28 | American Energy Partners Inc | Boerne, TX 78006 | Oil & Gas Operator | Dec 2011 |
| 29 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 30 | Ames Oil And Gas | | Oil & Gas Operator | Apr 1986 |
| 31 | Aminoil USA, Inc. | | Oil & Gas Operator | Jan 1985 |
| 32 | Amplify Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2023 |
| 33 | Ampolex Wy Inc | Gillette, WY 82716 | Oil & Gas Operator | Mar 1997 |
| 34 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Mar 2023 |
| 35 | Anadarko Minerals Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2023 |
| 36 | Anadarko Ogc Company | Houston, TX 77251 | Oil & Gas Operator | Dec 1998 |
| 37 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Jan 2023 |
| 38 | Anchor Bay Corporation | Denver, CO 80202 | Oil & Gas Operator | Jun 2007 |
| 39 | Anderson Management Company | Gillette, WY 82716 | Oil & Gas Operator | May 2016 |
| 40 | Anderson Oil Company | Burkburnett, TX 76354 | Oil & Gas Operator | Dec 2015 |
| 41 | Andrikopoulos A G | Cheyenne, WY 82009 | Oil & Gas Operator | Dec 1994 |
| 42 | Angus Petroleum Corporation | Chicago, IL 60660 | Oil & Gas Operator | Dec 2022 |
| 43 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 44 | Anschutz Corp | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 45 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Mar 2023 |
| 46 | Anschutz Oil Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Sep 2020 |
| 47 | Anschutz Pinedale Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2015 |
| 48 | Ant Hills Production | Lusk, WY 82225 | Oil & Gas Operator | Jan 2023 |
| 49 | Antelope Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2023 |
| 50 | Antelope Resources, Inc. | Billings, MT 59101 | Oil & Gas Operator | May 2017 |
| 51 | Antero Energy LLC | Denver, CO 80202 | Gas Operator | Nov 2003 |
| 52 | Antler Energy LLC | Baggs, WY 82321 | Oil & Gas Operator | Oct 2022 |
| 53 | Apache Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2023 |
| 54 | Apc Operating Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Oct 1996 |
| 55 | Apollo 17 Oil And Gas Inc | | Oil Operator | Feb 1988 |
| 56 | Apollo Drilling And Exploration | | Oil & Gas Operator | Oct 1980 |
| 57 | Apx Western Corporation | Denver, CO 80217 | Oil & Gas Operator | Sep 1991 |
| 58 | Aquarius Oil And Gas | Casper, WY 82601 | Oil & Gas Operator | Sep 2017 |
| 59 | Arabie, Inc. | Austin, TX 78735 | Oil & Gas Operator | Mar 2023 |
| 60 | Arapaho Petroleum Inc | Englewood, CO 80155 | Oil & Gas Operator | Nov 1998 |
| 61 | Arch Oil And Gas Company | Midland, TX 79702 | Oil & Gas Operator | Feb 1994 |
| 62 | Argent Energy (Us) Holdings Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Nov 2022 |
| 63 | Argentia Operating Company | | Oil Operator | Oct 1991 |
| 64 | Argo Petroleum Corp. | | Oil & Gas Operator | Dec 1989 |
| 65 | Arjay Oil Company | Salt Lake City, UT 84110 | Oil & Gas Operator | May 2000 |
| 66 | Arkland Producing Co Inc | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 67 | Arnell Oil Company | Centennial, CO 80122 | Oil Operator | Feb 2023 |
| 68 | Arrowhead Resources USA LTD | | Oil & Gas Operator | Dec 1992 |
| 69 | Asamera Oil Us Inc | Denver, CO 80201 | Oil & Gas Operator | Jul 1985 |
| 70 | Asher Associates, Inc. | Centennial, CO 80112 | Oil & Gas Operator | Aug 2016 |
| 71 | Ashland Exploration | | Oil & Gas Operator | May 1979 |
| 72 | Atasca Resources, Inc. | Houston, TX 77219 | Oil & Gas Operator | Mar 2023 |
| 73 | Atlantic Oil And Gas Development LLC | Rockledge, FL 32955 | Oil Operator | Jan 2023 |
| 74 | Atlantic Oil Corporation | | Oil & Gas Operator | Dec 1982 |
| 75 | Atlantic Richfield Company | Midland, TX 79702 | Oil & Gas Operator | Dec 2016 |
| 76 | Atr Energy Corp | Dallas, TX 75313 | Oil Operator | Jan 2023 |
| 77 | Atx Energy Partners LLC | Austin, TX 78716 | Oil & Gas Operator | Jan 2023 |
| 78 | Augustus Energy Partners LLC | Billings, MT 59102 | Oil & Gas Operator | Oct 2013 |
| 79 | Avalon Energy Corporation | | Oil & Gas Operator | Jul 1990 |
| 80 | Axem Resources Inc | Denver, CO 80202-4617 | Oil & Gas Operator | Jul 2013 |
| 81 | Axiom Energy LLC | Park City, UT 84098 | Oil Operator | Feb 2010 |
| 82 | Aztec Gas & Oil Corp. | Elephant Butte, NM 87935-0370 | Oil & Gas Operator | Mar 2005 |
| 83 | B J Oil Company | Corsicana, TX 75109 | Oil & Gas Operator | Mar 2023 |
| 84 | Baldes Henry | Riverton, WY 82501 | Oil Operator | Dec 1998 |
| 85 | Balidor Oil & Gas LLC | Houston, TX 77070 | Oil & Gas Operator | Oct 2021 |
| 86 | Ballard Petroleum Holdings LLC | Billings, MT 59104 | Oil & Gas Operator | Jan 2023 |
| 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 | Jan 2023 |
| 90 | Baney Well Service Inc | Denver, CO 80237 | 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 | Aurora, CO 80014 | Oil & Gas Operator | Feb 1998 |
| 95 | Barbe D F | Recluse, WY 82725 | Oil & Gas Operator | Dec 2000 |
| 96 | Barn Owls LLC | | Oil & Gas Operator | Jan 2023 |
| 97 | Barrel Springs Development Corp | Denver, CO 80202 | Oil & Gas Operator | Oct 1986 |
| 98 | Barrett Patrick | | Oil & Gas Operator | Apr 1988 |
| 99 | Basf Corporation | Houston, TX 77027 | Oil & Gas Operator | Nov 1992 |
| 100 | Basin Resources Corporation | Fair Oaks Ranch, TX 78015 | Oil Operator | May 2013 |