| 1 | Advantage Resources Inc | Broomfield, CO 80020 | Oil & Gas Operator | Jan 2024 |
| 2 | Aec Oil & Gas USA Inc | Denver, CO 80202 | Oil & Gas Operator | May 2004 |
| 3 | Alberta Gas Company | Vernal, UT 84078 | Oil & Gas Operator | Nov 2021 |
| 4 | Alta Energy Corporation | Midland, TX 79701 | Oil & Gas Operator | Apr 1995 |
| 5 | Altamont Energy Operating LLC | Greenwood VIlliage, CO 80111 | Oil & Gas Operator | Feb 2024 |
| 6 | Ambra Oil & Gas Company | Rangely, CO 81648 | Oil & Gas Operator | Jul 2006 |
| 7 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 8 | Amtech Energy Inc | Plymouth, IL 62367-1016 | Oil & Gas Operator | Dec 2021 |
| 9 | Anr Limited Inc/Coastal | Houston, TX 770460995 | Oil & Gas Operator | Dec 1987 |
| 10 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 11 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2024 |
| 12 | Apache Corporation | Houston, TX 77056 | Oil & Gas Operator | May 2024 |
| 13 | Apc Operating Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Oct 1996 |
| 14 | Arb Energy Utah, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2024 |
| 15 | Arch Oil And Gas Company | Midland, TX 79702 | Oil & Gas Operator | Feb 1994 |
| 16 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 17 | Ashley Valley Operating Company LLC | Orem, UT 84097 | Oil & Gas Operator | Feb 2024 |
| 18 | Augustus Energy Partners LLC | Billings, MT 59102 | Oil & Gas Operator | Feb 2014 |
| 19 | Aviara Energy Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2002 |
| 20 | Axia Energy II LLC | HGHLNDS Ranch, CO 80129 | Oil & Gas Operator | Jan 2020 |
| 21 | Axia Energy LLC | Hghlands Ranch, CO 80129-2258 | Oil & Gas Operator | Jun 2016 |
| 22 | Badger Oil Corporation | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2011 |
| 23 | Badlands Energy-Utah, LLC | Denver, CO 80237 | Oil & Gas Operator | Feb 2018 |
| 24 | Badlands Production Company | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Sep 2018 |
| 25 | Bainbridge Uinta LLC | Dallas, TX 75205 | Oil & Gas Operator | May 2021 |
| 26 | Ballard & Associates Inc | Billings, MT 59102-5406 | Oil & Gas Operator | Feb 2000 |
| 27 | Ballard Petroleum LLC | Billings, MT 59102-5406 | Oil & Gas Operator | Apr 2014 |
| 28 | Bar Mesa Resources Inc | Roosevelt, UT 84066 | Oil & Gas Operator | Sep 2012 |
| 29 | Barrett Resources Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 30 | Beard, J / McIlnay & Assoc | Casper, WY 82604 | Oil & Gas Operator | Aug 1996 |
| 31 | Beartooth Oil & Gas Company | Billings, MT 59103 | Oil & Gas Operator | Mar 2024 |
| 32 | Belco Development Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Feb 1994 |
| 33 | Belco Petroleum Corp | Grand Junction, CO | Oil & Gas Operator | Dec 1983 |
| 34 | Belnorth Petroleum Corporation | Midland, TX 79701 | Oil & Gas Operator | Feb 1991 |
| 35 | BHP Petroleum (Americas) | Houston, TX 77056-3020 | Oil & Gas Operator | Mar 1993 |
| 36 | Bill Barrett Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 37 | Birch Corporation | Denver, CO 80217 | Oil & Gas Operator | Dec 1989 |
| 38 | Bonneville Fuels Corp | Denver, CO 80290 | Oil & Gas Operator | Jun 2002 |
| 39 | Bow Valley Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1996 |
| 40 | Bridge Oil Company LP | Midland, TX 79702 | Oil & Gas Operator | May 1999 |
| 41 | Buttes Gas & Oil Co | | Oil & Gas Operator | Dec 2009 |
| 42 | Bwab Incorporated | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 43 | Caerus Uinta, LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2024 |
| 44 | California Oil Co | | Oil & Gas Operator | Aug 1965 |
| 45 | Cannon | Rock Springs, WY 82902 | Oil Operator | Feb 2024 |
| 46 | Carbon Energy Corporation (USA) | Denver, CO 80290 | Oil & Gas Operator | Jul 2004 |
| 47 | Carter Oil Co | | Oil & Gas Operator | Dec 2013 |
| 48 | CDX Rockies LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2005 |
| 49 | Celsius Energy Company | Denver, CO 80202-1558 | Oil & Gas Operator | Mar 2000 |
| 50 | Chandler & Associated Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 1999 |
| 51 | Chevron Oil Company | | Oil & Gas Operator | Dec 1983 |
| 52 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | May 2024 |
| 53 | Cig Exploration Inc | Houston, TX 77046 | Oil & Gas Operator | Nov 1999 |
| 54 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | May 2024 |
| 55 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | May 2024 |
| 56 | Cline Oil And Gas Company | Santa Fe, NM 87501 | Oil & Gas Operator | Sep 1994 |
| 57 | Clinton Oil Co | Wichita, KS 67202 | Oil & Gas Operator | Apr 1980 |
| 58 | CNG Producing | New Orleans, LA 70112-6000 | Oil & Gas Operator | Jun 2000 |
| 59 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 60 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2024 |
| 61 | Cochrane Resources Inc | Roosevelt, UT 84066 | Oil & Gas Operator | Feb 2024 |
| 62 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 63 | Columbia Gas Development | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 64 | Comanche Oil & Gas Corp | Salt Lake City, UT 84107-3075 | Oil & Gas Operator | May 2005 |
| 65 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 66 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | May 2024 |
| 67 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 68 | Continental Oil Co. | Durango, CO 81301 | Oil & Gas Operator | Dec 1983 |
| 69 | Coors Energy | Golden, CO 80402-0467 | Oil & Gas Operator | Sep 1992 |
| 70 | Coseka Resources USA LTD | Denver, CO 80202-1602 | Oil & Gas Operator | Jun 1988 |
| 71 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 72 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 73 | Cotton Petroleum Corp/Apc | Denver, CO 80203-4549 | Oil & Gas Operator | Nov 1990 |
| 74 | Crain & Griffith DRL Co | | Oil Operator | Jun 1963 |
| 75 | Crescent Point Energy Us Corp | Denver, CO 80202 | Oil & Gas Operator | Mar 2024 |
| 76 | D & J Oil Co | Kermit, TX 79745 | Oil & Gas Operator | May 2024 |
| 77 | Dalen Resources Oil & Gas | Dallas, TX 75206-3922 | Oil & Gas Operator | Jan 1996 |
| 78 | Davis Oil Company | Pawhuska, OK 74056 | Oil & Gas Operator | Jun 2018 |
| 79 | De Kalb Agric Assn Inc | Vernal, UT | Oil & Gas Operator | Jun 1965 |
| 80 | Del-Rio Resources Inc | Vernal, UT 84079 | Oil & Gas Operator | Jan 2018 |
| 81 | Delhi-Taylor Oil Corp | | Oil & Gas Operator | Dec 1974 |
| 82 | Delhi-Trading LLC | Durango, CO 81301 | Oil & Gas Operator | Dec 2023 |
| 83 | Devon Energy Operating Corp | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2013 |
| 84 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2024 |
| 85 | Diamond Shamrock Corp | Amarillo, TX 79105 | Oil & Gas Operator | Jan 1987 |
| 86 | Diamond Shamrock Expl | Dallas, TX 75201 | Oil & Gas Operator | May 1987 |
| 87 | Discovery Natural Resources LLC | Denver, CO 80202 | Oil & Gas Operator | May 2024 |
| 88 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 89 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 90 | Dougherty, H W | Petaluma, CA 94954 | Gas Operator | Oct 2019 |
| 91 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 92 | El Paso Natural Gas Company | El Paso, TX 79978 | Oil & Gas Operator | Apr 2013 |
| 93 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | May 2024 |
| 94 | Elk Production LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2011 |
| 95 | Elk Production Uintah LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 96 | Elk Resources, LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2011 |
| 97 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 98 | Enduring Resources, LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Feb 2024 |
| 99 | Energy Reserves Group | Houston, TX 770563020 | Oil & Gas Operator | Apr 1996 |
| 100 | Enerplus Resources USA Corporation | Denver, CO 80202 | Oil & Gas Operator | Mar 2024 |