| 1 | Abo Petroleum Corp | Artesia, NM 88210 | Oil & Gas Operator | Jul 1988 |
| 2 | Adams, Frank B | Corpus Christi, TX 78476 | Oil & Gas Operator | Feb 1988 |
| 3 | Advantage Resources Inc | Broomfield, CO 80020 | Oil & Gas Operator | Jun 2025 |
| 4 | Afe Management Limited | Concord, Ontario, L4K 4G4 | Oil & Gas Operator | Sep 1987 |
| 5 | Alberta Gas Company | Vernal, UT 84078 | Oil & Gas Operator | Nov 2021 |
| 6 | Albritton Resources Inc | Dallas, TX 75206 | Oil & Gas Operator | Feb 2001 |
| 7 | Alco Oil & Gas | Lafayette, LA 70130 | Oil & Gas Operator | Dec 1970 |
| 8 | Alta Energy Corporation | Midland, TX 79701 | Oil & Gas Operator | Apr 1995 |
| 9 | Altamont Energy Operating LLC | Greenwood VIlliage, CO 80111 | Oil & Gas Operator | Sep 2024 |
| 10 | Altex Oil Corp | Breckenridge, CO 80424-1057 | Oil & Gas Operator | Dec 1999 |
| 11 | Amax Petroleum Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2012 |
| 12 | Ambra Oil & Gas Company | Rangely, CO 81648 | Oil & Gas Operator | Jul 2006 |
| 13 | American Helium Operating, LLC | Katy, TX 77494 | Oil & Gas Operator | Aug 2025 |
| 14 | American Quasar Petroleum | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 1985 |
| 15 | Amoco Production Company | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 16 | Amoco Rocmount Company | Denver, CO 80201 | Oil & Gas Operator | Jan 1998 |
| 17 | Amtech Energy Inc | Plymouth, IL 62367-1016 | Oil & Gas Operator | Dec 2021 |
| 18 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Nov 2025 |
| 19 | Anadarko Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Aug 2025 |
| 20 | Anr Limited Inc/Coastal | Houston, TX 770460995 | Oil & Gas Operator | Dec 1987 |
| 21 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 22 | Anschutz Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 23 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Nov 2025 |
| 24 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Nov 2025 |
| 25 | Apc Operating Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Oct 1996 |
| 26 | Appaloosa Operating Company LLC | The Woodlands, TX 77387 | Oil & Gas Operator | Apr 2019 |
| 27 | Arb Energy Utah, LLC | Katy, TX 77494 | Oil & Gas Operator | Aug 2025 |
| 28 | Arch Oil And Gas Company | Midland, TX 79702 | Oil & Gas Operator | Feb 1994 |
| 29 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 30 | Asamera Oil Us Inc | Denver, CO 80201 | Oil & Gas Operator | Jul 1985 |
| 31 | Ashley Valley Operating Company LLC | Orem, UT 84097 | Oil & Gas Operator | Jun 2025 |
| 32 | Augustus Energy Partners LLC | Billings, MT 59102 | Oil & Gas Operator | Oct 2013 |
| 33 | Avad Operating, LLC | Dallas, TX 75201 | Oil & Gas Operator | Nov 2025 |
| 34 | Aviara Energy Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2002 |
| 35 | Axia Energy II LLC | HGHLNDS Ranch, CO 80129 | Oil & Gas Operator | Jan 2020 |
| 36 | Axia Energy LLC | Hghlands Ranch, CO 80129-2258 | Oil & Gas Operator | Apr 2015 |
| 37 | Aztec Oil Co | | Oil & Gas Operator | Dec 1977 |
| 38 | B L Oil And Gas | Loco Hills, NM 88255 | Oil & Gas Operator | Aug 2010 |
| 39 | Babcock & Brown Energy Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2007 |
| 40 | Badger Oil Corporation | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2011 |
| 41 | Badlands Energy-Utah, LLC | Denver, CO 80237 | Oil & Gas Operator | Feb 2018 |
| 42 | Badlands Production Company | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Sep 2018 |
| 43 | Bainbridge Uinta LLC | Dallas, TX 75205 | Oil & Gas Operator | May 2021 |
| 44 | Ballard & Associates Inc | Billings, MT 59102-5406 | Oil & Gas Operator | Feb 2000 |
| 45 | Ballard Petroleum LLC | Billings, MT 59102-5406 | Oil & Gas Operator | Apr 2014 |
| 46 | Bar Mesa Resources Inc | Roosevelt, UT 84066 | Oil & Gas Operator | Sep 2012 |
| 47 | Barrett Resources Corporation | Denver, CO 80202 | Oil & Gas Operator | Aug 2003 |
| 48 | Basf Corporation | Houston, TX 77027 | Oil & Gas Operator | Nov 1992 |
| 49 | Bayless Robert L Producer | Denver, CO 80293 | Oil & Gas Operator | Sep 2003 |
| 50 | Beard, J / McIlnay & Assoc | Casper, WY 82604 | Oil & Gas Operator | Aug 1996 |
| 51 | Beartooth Oil & Gas Company | Billings, MT 59103 | Oil & Gas Operator | Aug 2025 |
| 52 | Belco Development Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Feb 1994 |
| 53 | Belco Petroleum Corp | Grand Junction, CO | Oil & Gas Operator | Dec 1983 |
| 54 | Belnorth Petroleum Corporation | Midland, TX 79701 | Oil & Gas Operator | Feb 1991 |
| 55 | Benson-Montin-Greer DRL | Farmington, NM 87402 | Oil & Gas Operator | Sep 2025 |
| 56 | Berry Petroleum Company | Denver, CO 80202 | Oil & Gas Operator | Feb 2014 |
| 57 | Berry Petroleum Company LLC | Bakersfield, CA 93311 | Oil & Gas Operator | Aug 2025 |
| 58 | BHP Petroleum (Americas) | Houston, TX 77056-3020 | Oil & Gas Operator | Mar 1993 |
| 59 | BHP Petroleum Company Inc | Houston, TX 77057 | Oil & Gas Operator | Jun 2016 |
| 60 | Bill Barrett Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 61 | Birch Corporation | Denver, CO 80217 | Oil & Gas Operator | Dec 1989 |
| 62 | Bishop Petroleum Corp | Arvada, CO 80002 | Oil & Gas Operator | Oct 1993 |
| 63 | Blue Tip Castlegate, Inc | Erie, KS 66733 | Gas Operator | Jun 2016 |
| 64 | Boardwalk Petroleum Inc | | Oil & Gas Operator | Dec 1983 |
| 65 | Bog Inc (Bowers) | Grand Junction, CO 81502 | Oil & Gas Operator | Jan 1989 |
| 66 | Bonneville Fuels Corp | Denver, CO 80290 | Oil & Gas Operator | Jun 2002 |
| 67 | Bow Valley Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1996 |
| 68 | Bowers Oil & Gas, Inc. | Grand Junction, CO 81505-1097 | Oil & Gas Operator | Nov 2022 |
| 69 | BP America Production Company | Denver, CO 80202 | Oil & Gas Operator | Jul 2025 |
| 70 | Bridge Oil Company LP | Midland, TX 79702 | Oil & Gas Operator | May 1999 |
| 71 | Brinkerhoff Drilling Co | | Oil & Gas Operator | Jul 1975 |
| 72 | Broadhead, Walter | Grand Junction, CO 81502 | Oil & Gas Operator | Mar 2005 |
| 73 | Bta Oil Producers | Midland, TX 79701 | Oil & Gas Operator | Sep 2009 |
| 74 | Buckhorn Petroleum | | Oil & Gas Operator | Dec 1983 |
| 75 | Burlington Resources O&G | Midland, TX 79710-1810 | Oil & Gas Operator | Mar 1997 |
| 76 | Burr Oil & Gas | Farmington, NM 87499 | Oil & Gas Operator | Feb 2000 |
| 77 | Burton/Hawks Inc | Casper, WY 82602 | Oil & Gas Operator | Sep 1993 |
| 78 | Buttes Gas & Oil Co | | Oil & Gas Operator | Dec 2009 |
| 79 | Bwab Incorporated | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 80 | C & K Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1984 |
| 81 | C C Co | Holladay, UT 84124 | Oil & Gas Operator | Jan 2020 |
| 82 | C.S.V. Oil Exploration Co | West Jordan, UT 84088 | Gas Operator | Aug 2025 |
| 83 | Caerus Uinta, LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2025 |
| 84 | California Oil Co | | Oil & Gas Operator | Aug 1965 |
| 85 | Campbell, G S | Park City, UT 84060 | Oil & Gas Operator | Apr 1991 |
| 86 | Cannon | Rock Springs, WY 82902 | Oil Operator | Jul 2025 |
| 87 | Cap Energy LLC | Greeley, CO 80634 | Oil & Gas Operator | Aug 2019 |
| 88 | Capitol Operating Group, LLC | Lafayette, LA 70503-5334 | Oil & Gas Operator | Sep 2025 |
| 89 | Carbon Energy Corporation (USA) | Denver, CO 80290 | Oil & Gas Operator | Jul 2004 |
| 90 | Carter Oil Co | | Oil & Gas Operator | Dec 2013 |
| 91 | Celsius Energy Company | Denver, CO 80202-1558 | Oil & Gas Operator | Mar 2000 |
| 92 | Central Resources, Inc. | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 93 | Champlin Petroleum Co. | Rock Springs, WY 82902 | Oil & Gas Operator | Mar 1991 |
| 94 | Chandler & Associated Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 1999 |
| 95 | Chevron Oil Company | | Oil & Gas Operator | Dec 1983 |
| 96 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Nov 2025 |
| 97 | Cig Exploration Inc | Houston, TX 77046 | Oil & Gas Operator | Nov 1999 |
| 98 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | Nov 2025 |
| 99 | Citation Oil & Gas Corp | Houston, TX 77269 | Oil & Gas Operator | Nov 2025 |
| 100 | Cities Serv Oil & Gas Corp | Oklahoma City, OK 73112 | Oil & Gas Operator | Sep 1964 |