| 1 | 4W Ranch | Newcastle, WY 82701 | Oil Operator | Apr 2008 |
| 2 | Accidental Oil Company Inc | Newcastle, WY 82701 | Oil & Gas Operator | Feb 2021 |
| 3 | Adairco LLC | Fort Collins, CO 80525 | Oil & Gas Operator | Feb 2010 |
| 4 | Adams H D LLC | Moorcroft, WY 82721 | Oil & Gas Operator | Nov 2025 |
| 5 | Adobe Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 6 | Allen And Crouch | Casper, WY 82602 | Oil & Gas Operator | Mar 2020 |
| 7 | Alpha Petrovision Us Inc | Canada, 00100 | Oil & Gas Operator | May 2013 |
| 8 | Am-West Petroleum Inc | Upton, WY 82730 | Oil & Gas Operator | Sep 2015 |
| 9 | Ames Oil And Gas | | Oil & Gas Operator | Apr 1986 |
| 10 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2025 |
| 11 | Apollo Drilling And Exploration | | Oil & Gas Operator | Oct 1980 |
| 12 | Aquarius Oil And Gas | Casper, WY 82601 | Oil & Gas Operator | Sep 2017 |
| 13 | Arapaho Petroleum Inc | Englewood, CO 80155 | Oil & Gas Operator | Nov 1998 |
| 14 | Asamera Oil Us Inc | Denver, CO 80201 | Oil & Gas Operator | Jul 1985 |
| 15 | Atlantic Oil Corporation | Denver, CO 80206 | Oil & Gas Operator | Dec 1982 |
| 16 | Atlantic Richfield Company | Plano, TX 75074 | Oil & Gas Operator | Dec 2016 |
| 17 | B J Oil Company | Corsicana, TX 75109 | Oil & Gas Operator | Dec 2025 |
| 18 | Balsam R C | | Oil & Gas Operator | Apr 1991 |
| 19 | Banks Operating Company | | Oil & Gas Operator | Jul 1989 |
| 20 | Barn Owls LLC | | Oil & Gas Operator | Oct 2025 |
| 21 | Basf Corporation | Houston, TX 77027 | Oil & Gas Operator | Nov 1992 |
| 22 | Bataa Oil Inc | Arvada, CO 80005 | Oil & Gas Operator | Oct 2025 |
| 23 | Baytex Energy USA LLC | Denver, CO 80202 | Oil & Gas Operator | Nov 2014 |
| 24 | Bell Resources Inc | Billings, MT 59104 | Oil & Gas Operator | Jun 2016 |
| 25 | Big Basin Petroleum LLC | Gillette, WY 82717 | Oil & Gas Operator | Oct 2008 |
| 26 | Bill Barrett Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 27 | Bing Harold C | Newcastle, WY 82701 | Oil Operator | Jun 1992 |
| 28 | Black Gold Services Inc | Casper, WY 82644 | Oil & Gas Operator | Oct 2025 |
| 29 | Black Hills Exploration & Production Inc | Newcastle, WY 82701 | Oil & Gas Operator | Mar 2018 |
| 30 | Black Thunder Oil LLC | Gillette, WY 82717 | Oil & Gas Operator | Sep 2025 |
| 31 | Boggy Creek Production | Newcastle, WY 82701 | Oil & Gas Operator | Apr 2012 |
| 32 | BP Exploration Inc | | Oil & Gas Operator | May 1993 |
| 33 | Bradford Oil Company | Denver, CO 80249 | Oil & Gas Operator | Oct 2025 |
| 34 | Bradley Jr Jack C | Casper, WY 82601 | Oil & Gas Operator | Apr 2009 |
| 35 | Bradley SR Jack C | Newcastle, WY 82701 | Oil Operator | Jun 2010 |
| 36 | Bronco Oil & Gas Co | Casper, WY 82602 | Oil & Gas Operator | Oct 1987 |
| 37 | Brown Doug & Larita | Newcastle, WY 82701 | Oil & Gas Operator | Jun 2025 |
| 38 | Burnett Oil Co Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 39 | Burr Oil & Gas Inc | Farmington, NM 87499 | Oil & Gas Operator | Oct 2019 |
| 40 | BW Oil LLC | Hamel, MN 55340 | Oil Operator | Jun 2015 |
| 41 | Bwab Incorporated | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 42 | Capitol Oil & Gas Corporation | Centennial, WY 82055 | Oil Operator | Feb 2006 |
| 43 | Central Operating Inc | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 44 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Nov 2025 |
| 45 | Chemily Management Company | Cypress, TX 77429 | Oil & Gas Operator | Apr 2023 |
| 46 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Dec 2025 |
| 47 | Chipcore LLC | Casper, WY 82601 | Oil & Gas Operator | Oct 2025 |
| 48 | Chriscor Oil & Gas | Plana, TX 75075 | Oil & Gas Operator | Jul 1987 |
| 49 | Christensen Ranch | Newcastle, WY 82701 | Oil Operator | Aug 2021 |
| 50 | CKT Energy LLC | Dallas, TX 75379 | Oil & Gas Operator | Sep 2020 |
| 51 | Colorado Oil & Gas Corporation | | Oil & Gas Operator | Sep 1984 |
| 52 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 53 | Columbine Exploration Corp | Englewood, CO 80111 | Oil & Gas Operator | Aug 1998 |
| 54 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 55 | Common Energy Inc | Douglas, WY 82633 | Oil & Gas Operator | Aug 1995 |
| 56 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 57 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Dec 2025 |
| 58 | Contango Rocky Mountain Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2020 |
| 59 | Cook D L | Holliday, TX 76366 | Oil & Gas Operator | Dec 2008 |
| 60 | Cork Petroleum Corporation | Thermopolis, WY 82443 | Oil & Gas Operator | Apr 2012 |
| 61 | Coronado Oil Company | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 62 | Cottonwood Oil Inc | Worland, WY 82401 | Oil & Gas Operator | Jun 1988 |
| 63 | Creek Oil Company | Colorado Springs, CO 80906 | Oil & Gas Operator | Aug 2001 |
| 64 | D & B Oil Company | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 65 | Davis & Tharel | | Oil & Gas Operator | Dec 1988 |
| 66 | Davis Bobby J | Upton, WY 82730 | Oil & Gas Operator | Oct 1989 |
| 67 | Davis Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 1988 |
| 68 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 69 | Diamond B Industries Inc | Belle Fourche, SD 57717 | Oil & Gas Operator | Apr 2010 |
| 70 | Diamondback Oil Partners LLP | Arvada, CO 80004 | Oil & Gas Operator | Sep 2016 |
| 71 | Discovery Oil LTD | Los Angeles, CA 90067 | Oil & Gas Operator | Jan 1993 |
| 72 | DNR Oil And Gas, Inc. | Englewood, CO 80155 | Oil & Gas Operator | Nov 2025 |
| 73 | Dol Resources Inc | Rowlett, TX 75088 | Oil & Gas Operator | Nov 2025 |
| 74 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 75 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Dec 2025 |
| 76 | Eberspecher Drilling Inc | Casper, WY 82601 | Oil & Gas Operator | Dec 2000 |
| 77 | Eblen Frank Syndicate Inc | Atlantic, IA 50022 | Oil & Gas Operator | Jul 2014 |
| 78 | Emc Energy | | Oil & Gas Operator | Jun 1985 |
| 79 | Encana Energy Resources Inc | Denver, CO 80202-2828 | Oil & Gas Operator | Feb 2024 |
| 80 | Energetics Inc | Englewood, CO 80155 | Oil & Gas Operator | Aug 1985 |
| 81 | Energy Production Co | Pittsburgh, PA 15241-3949 | Oil & Gas Operator | Dec 1994 |
| 82 | Enstar Petroleum Inc | | Oil & Gas Operator | Apr 1985 |
| 83 | Envirosearch Corporation | | Oil Operator | Dec 1992 |
| 84 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 85 | Equitable Resources Energy Company | Big Stone Gap, VA 24219 | Oil & Gas Operator | Dec 1997 |
| 86 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Dec 2025 |
| 87 | F & J Oil LLC | Newcastle, WY 82701 | Oil & Gas Operator | Oct 2015 |
| 88 | Farnsworth & Kaiser Oil Company | Newcastle, WY 82701 | Oil & Gas Operator | Sep 2012 |
| 89 | FDF Resources | Newcastle, WY 82701 | Oil & Gas Operator | Nov 2025 |
| 90 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 91 | Flying J Oil & Gas Inc | North Salt Lake, UT 84054 | Oil & Gas Operator | Dec 2009 |
| 92 | Fuel Resources Development Co | Denver, CO 80202 | Oil & Gas Operator | Feb 1994 |
| 93 | Gallagher T P | Boulder, CO 80303 | Oil Operator | Apr 2019 |
| 94 | Gasamat Oil Corp Of Colorado | Boulder, CO 80303 | Oil Operator | Oct 2025 |
| 95 | Getty Oil Company | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 96 | GLG Energy LP | Austin, TX 78701 | Oil & Gas Operator | Jun 1994 |
| 97 | Goldmark Engineering Inc | Casper, WY 82602 | Oil & Gas Operator | Oct 2004 |
| 98 | Gould Joseph B | Las Vegas, NV 89101 | Oil & Gas Operator | Apr 2001 |
| 99 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 100 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |