| 1 | Abo Petroleum Corp | Artesia, NM 88210 | Oil & Gas Operator | Jul 1988 |
| 2 | Adak Energy Corporation | Salt Lake City, UT 84106 | Gas Operator | Apr 1992 |
| 3 | Adams, Frank B | Corpus Christi, TX 78476 | Oil & Gas Operator | Feb 1988 |
| 4 | Advantage Resources Inc | Denver, CO 80203 | Oil & Gas Operator | Jan 2020 |
| 5 | Afe Management Limited | Concord, Ontario, L4K 4G4 | Oil & Gas Operator | Sep 1987 |
| 6 | Albritton Resources Inc | Dallas, TX 75225 | Oil & Gas Operator | Jul 1986 |
| 7 | Alco Oil & Gas | Lafayette, LA 70130 | Oil & Gas Operator | Dec 1970 |
| 8 | Alta Energy Corporation | Oklahoma City, OK 731028260 | Oil & Gas Operator | Apr 1995 |
| 9 | Altamont Energy Operating LLC | Greenwood VIlliage, CO 80111 | Oil & Gas Operator | Mar 2020 |
| 10 | Amax Petroleum Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2015 |
| 11 | Ambra Oil & Gas Company | Rangely, CO 81648 | Oil & Gas Operator | Jul 2006 |
| 12 | American Quasar Petroleum | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 1985 |
| 13 | Amoco Production Co. | Chicago, IL 60601-7125 | Oil & Gas Operator | Jun 2015 |
| 14 | Amoco Rocmount Company | Denver, CO 80201 | Oil & Gas Operator | Jan 1998 |
| 15 | Amtech Energy Inc | Plymouth, IL 62367-1016 | Oil & Gas Operator | Dec 2017 |
| 16 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Dec 2020 |
| 17 | Anadarko Petroleum Corporation | Houston, TX 77251-1330 | Oil & Gas Operator | Feb 2020 |
| 18 | Anr Limited Inc/Coastal | Houston, TX 770460995 | Oil & Gas Operator | Dec 1987 |
| 19 | Anr Production Company | Denver, CO 80201-0749 | Oil & Gas Operator | Sep 2017 |
| 20 | Anschutz Corporation, The | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 21 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2020 |
| 22 | Apache Corporation | Houston, TX 77056 | Oil & Gas Operator | Jun 2020 |
| 23 | Apc Operating Partnership | Denver, CO 802034520 | Oil & Gas Operator | Oct 1996 |
| 24 | Appaloosa Operating Company LLC | The Woodlands, TX 77387 | Oil & Gas Operator | Apr 2019 |
| 25 | Arb Energy Utah, LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2020 |
| 26 | Arch Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Jan 1992 |
| 27 | Arco Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Mar 2006 |
| 28 | Ashley Valley Operating Company LLC | Orem, UT 84097 | Oil & Gas Operator | Mar 2020 |
| 29 | Augustus Energy Partners LLC | Billings, MT 59102 | Oil & Gas Operator | Oct 2013 |
| 30 | Avad Operating, LLC | Dallas, TX 75201 | Oil & Gas Operator | Jun 2020 |
| 31 | Aviara Energy Corporation | Houston, TX 77251-1350 | Oil & Gas Operator | May 2013 |
| 32 | Axia Energy II LLC | Highlands Ranch, CO 80129 | Oil & Gas Operator | Jan 2020 |
| 33 | Axia Energy LLC | Hghlands Ranch, CO 80129-2258 | Oil & Gas Operator | Jun 2016 |
| 34 | Aztec Oil Co | | Oil & Gas Operator | Dec 1977 |
| 35 | B L Oil And Gas | Grand Junction, CO 81503 | Oil & Gas Operator | Aug 2010 |
| 36 | Babcock & Brown Energy Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2007 |
| 37 | Badger Oil Corporation | Lafayette, LA 70505 | Oil & Gas Operator | Jul 2014 |
| 38 | Badlands Energy-Utah, LLC | Denver, CO 80237 | Oil & Gas Operator | Feb 2018 |
| 39 | Badlands Production Company | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Sep 2018 |
| 40 | Bainbridge Uinta LLC | Dallas, TX 75206 | Oil & Gas Operator | Mar 2020 |
| 41 | Ballard Petroleum LLC | Billings, MT 59102 | Oil & Gas Operator | Dec 2001 |
| 42 | Bar Mesa Resources Inc | Roosevelt, UT 84066 | Oil & Gas Operator | Sep 2012 |
| 43 | Barrett Resources Corporation | Denver, CO 80202-2120 | Oil & Gas Operator | Dec 2009 |
| 44 | Basf Corporation | Houston, TX 77027 | Oil & Gas Operator | Nov 1992 |
| 45 | Bayless, Robert L Producer | Denver, CO 80293 | Oil & Gas Operator | Sep 2003 |
| 46 | Beard, J / McIlnay & Assoc | Casper, WY 82604 | Oil & Gas Operator | Aug 1996 |
| 47 | Beartooth Oil & Gas Company | Billings, MT 59103 | Oil & Gas Operator | Dec 2020 |
| 48 | Belco Development Corp | Vernal, UT 84078 | Oil & Gas Operator | Jul 1989 |
| 49 | Belco Petroleum Corp | Grand Junction, CO | Oil & Gas Operator | Dec 1983 |
| 50 | Belnorth Petroleum Corp | Vernal, UT 84078 | Oil & Gas Operator | Oct 1987 |
| 51 | Benson-Montin-Greer DRL | Farmington, NM 87402 | Oil & Gas Operator | Apr 2020 |
| 52 | Berry Petroleum Company | Denver, CO 80202 | Oil & Gas Operator | Feb 2014 |
| 53 | Berry Petroleum Company LLC | Bakersfield, CA 93309-0422 | Oil & Gas Operator | Mar 2020 |
| 54 | BHP Petroleum (Americas) | Houston, TX 77056-3020 | Oil & Gas Operator | Mar 1993 |
| 55 | BHP Petroleum Company Inc | Houston, TX 77057 | Oil & Gas Operator | Nov 2004 |
| 56 | Bill Barrett Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 57 | Birch Corporation | Denver, CO 80217 | Oil & Gas Operator | Dec 1989 |
| 58 | Bishop Petroleum Corp | Arvada, CO 80002 | Oil & Gas Operator | Oct 1993 |
| 59 | Blue Tip Castlegate, Inc | Erie, KS 66733 | Gas Operator | Jun 2016 |
| 60 | Boardwalk Petroleum Inc | | Oil & Gas Operator | Dec 1983 |
| 61 | Bog Inc (Bowers) | Grand Junction, CO 81502 | Oil & Gas Operator | Jan 1989 |
| 62 | Bonneville Fuels Corp | Denver, CO 80290 | Oil & Gas Operator | Jun 2002 |
| 63 | Bow Valley Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1996 |
| 64 | Bowers Oil & Gas, Inc. | Grand Junction, CO 81505-1097 | Oil & Gas Operator | Apr 2020 |
| 65 | BP America Production Company | Houston, TX 77079 | Oil & Gas Operator | Dec 2020 |
| 66 | Bridge Oil Company, L. P. | Dallas, TX 75251 | Oil & Gas Operator | Mar 2011 |
| 67 | Brinkerhoff Drilling Co | | Oil & Gas Operator | Jul 1975 |
| 68 | Broadhead, Walter | Grand Junction, CO 81502 | Oil & Gas Operator | Mar 2005 |
| 69 | Bta Oil Producers | Midland, TX 79701 | Oil & Gas Operator | Sep 2009 |
| 70 | Buckhorn Petroleum | | Oil & Gas Operator | Dec 1983 |
| 71 | Burlington Resources O&G | Midland, TX 79710-1810 | Oil & Gas Operator | Mar 1997 |
| 72 | Burr Oil & Gas | Farmington, NM 87499 | Oil & Gas Operator | Feb 2000 |
| 73 | Burton/Hawks Inc | Casper, WY 82602 | Oil & Gas Operator | Sep 1993 |
| 74 | Buttes Gas & Oil Co | | Oil & Gas Operator | Dec 2009 |
| 75 | Buzzards Bench, LLC | Allen, TX 75002 | Gas Operator | Mar 2020 |
| 76 | Bwab Incorporated | Denver, CO 80202-4026 | Oil & Gas Operator | Aug 1996 |
| 77 | C & K Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1984 |
| 78 | C C Co | Holladay, UT 84124 | Oil & Gas Operator | Jul 2018 |
| 79 | California Oil Co | | Oil & Gas Operator | Aug 1965 |
| 80 | Campbell, G S | Park City, UT 84060 | Oil & Gas Operator | Apr 1991 |
| 81 | Cannon | Rock Springs, WY 82902 | Oil Operator | Apr 2020 |
| 82 | Cap Energy LLC | Greeley, CO 80634 | Oil & Gas Operator | Aug 2019 |
| 83 | Capitol Operating Group, LLC | Lafayette, LA 70503-5334 | Oil & Gas Operator | Apr 2020 |
| 84 | Carbon Energy Corporation (USA) | Denver, CO 80290 | Oil & Gas Operator | Jul 2004 |
| 85 | Carter Oil Co | | Oil & Gas Operator | Dec 2013 |
| 86 | Celsius Energy Company | Denver, CO 80202-1558 | Oil & Gas Operator | Mar 2000 |
| 87 | Central Resources, Inc. | Denver, CO 80203 | Oil & Gas Operator | Jan 2020 |
| 88 | CH4-Finley Operating, LLC | Fort Worth, TX 76109 | Oil & Gas Operator | Mar 2020 |
| 89 | Champlin Petroleum Co. | Rock Springs, WY 82902 | Oil & Gas Operator | Mar 1991 |
| 90 | Chandler & Associated Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 1999 |
| 91 | Chevron Oil Company | | Oil & Gas Operator | Dec 1983 |
| 92 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Jun 2020 |
| 93 | Chorney Oil Co | Denver, CO 80203 | Oil & Gas Operator | Mar 1975 |
| 94 | Cig Exploration, Inc. | Denver, CO 80201-0749 | Oil & Gas Operator | Feb 1997 |
| 95 | Cimarex Energy Co. | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2020 |
| 96 | Cisco Drilling & Devel | | Gas Operator | Dec 1983 |
| 97 | Cisco Expro LLC | Park City, UT 84098-5178 | Oil & Gas Operator | Nov 2009 |
| 98 | Citation Oil & Gas Corp. | Houston, TX 77269-688 | Oil & Gas Operator | Dec 2020 |
| 99 | Cities Serv Oil & Gas Corp | Oklahoma City, OK 73112 | Oil & Gas Operator | Sep 1964 |
| 100 | Clayton Investment | Farmington, NM 87401 | Oil & Gas Operator | Jun 1995 |