| 1 | Adak Energy Corporation | Salt Lake City, UT 84106 | Gas Operator | Apr 1992 |
| 2 | Adams & Dizdar | | Gas Operator | Jun 1981 |
| 3 | Adams, Frank B | Corpus Christi, TX 78476 | Oil & Gas Operator | Feb 1988 |
| 4 | Altex Oil Corp | Breckenridge, CO 80424-1057 | Oil & Gas Operator | Dec 1999 |
| 5 | Amax Petroleum Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2012 |
| 6 | Ambra Oil & Gas Company | Rangely, CO 81648 | Oil & Gas Operator | Jul 2006 |
| 7 | Amoco Production Company | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 8 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Feb 2026 |
| 9 | Anschutz Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 10 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Feb 2026 |
| 11 | Arb Energy Utah, LLC | Katy, TX 77494 | Oil & Gas Operator | Dec 2025 |
| 12 | Arch Oil And Gas Company | Midland, TX 79702 | Oil & Gas Operator | Feb 1994 |
| 13 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 14 | Augustus Energy Partners LLC | Billings, MT 59102 | Oil & Gas Operator | Oct 2013 |
| 15 | Aviara Energy Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2002 |
| 16 | B L Oil And Gas | Loco Hills, NM 88255 | Oil & Gas Operator | Aug 2010 |
| 17 | Babcock & Brown Energy Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2007 |
| 18 | Beartooth Oil & Gas Company | Billings, MT 59103 | Oil & Gas Operator | Dec 2025 |
| 19 | Belco Development Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Feb 1994 |
| 20 | Belco Petroleum Corp | Grand Junction, CO | Oil & Gas Operator | Dec 1983 |
| 21 | Belnorth Petroleum Corporation | Midland, TX 79701 | Oil & Gas Operator | Feb 1991 |
| 22 | Benson-Montin-Greer DRL | Farmington, NM 87402 | Oil & Gas Operator | Jan 2026 |
| 23 | Bill Barrett Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 24 | Birch Corporation | Denver, CO 80217 | Oil & Gas Operator | Dec 1989 |
| 25 | Boardwalk Petroleum Inc | | Oil & Gas Operator | Dec 1983 |
| 26 | Bog Inc (Bowers) | Grand Junction, CO 81502 | Oil & Gas Operator | Jan 1989 |
| 27 | Bonneville Fuels Corp | Denver, CO 80290 | Oil & Gas Operator | Jun 2002 |
| 28 | Bowers Oil & Gas, Inc. | Grand Junction, CO 81505-1097 | Oil & Gas Operator | Nov 2022 |
| 29 | Broadhead, Walter | Grand Junction, CO 81502 | Oil & Gas Operator | Mar 2005 |
| 30 | Buckhorn Petroleum | | Oil & Gas Operator | Dec 1983 |
| 31 | Burlington Resources O&G | Midland, TX 79710-1810 | Oil & Gas Operator | Mar 1997 |
| 32 | Burton/Hawks Inc | Casper, WY 82602 | Oil & Gas Operator | Sep 1993 |
| 33 | Bwab Incorporated | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 34 | C C Co | Holladay, UT 84124 | Oil & Gas Operator | Jan 2020 |
| 35 | C.S.V. Oil Exploration Co | West Jordan, UT 84088 | Gas Operator | Nov 2025 |
| 36 | Carbon Energy Corporation (USA) | Denver, CO 80290 | Oil & Gas Operator | Jul 2004 |
| 37 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 38 | Cisco Drilling & Devel | | Gas Operator | Dec 1983 |
| 39 | Cisco Expro LLC | Park City, UT 84098-5178 | Oil & Gas Operator | Nov 2009 |
| 40 | Clayton Investment | Farmington, NM 87401 | Oil & Gas Operator | Jun 1995 |
| 41 | Cochrane Resources Inc | Roosevelt, UT 84066 | Oil & Gas Operator | Jan 2026 |
| 42 | Colorado Drilling Company | Grand Junction, CO 81501 | Oil Operator | Jan 1990 |
| 43 | Columbia Gas Development | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 44 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 45 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 46 | Coseka Resources USA LTD | Denver, CO 80202-1602 | Oil & Gas Operator | Jun 1988 |
| 47 | Credo Petroleum Corporation | Denver, CO 80202 | Oil & Gas Operator | Jan 2013 |
| 48 | Crest Oil Corp | | Gas Operator | Dec 1983 |
| 49 | Crystal Carbon Company | | Gas Operator | Dec 1930 |
| 50 | D & D Oil Company | Dayton, TX 77535 | Oil & Gas Operator | Feb 2026 |
| 51 | Davis Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 1988 |
| 52 | Delhi-Taylor Oil Corp | | Oil & Gas Operator | Dec 1974 |
| 53 | Delta Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2024 |
| 54 | Diamond Shamrock Corp | Amarillo, TX 79105 | Oil & Gas Operator | Jan 1987 |
| 55 | Diamond Shamrock Expl | Dallas, TX 75201 | Oil & Gas Operator | May 1987 |
| 56 | Dougherty, H W | Petaluma, CA 94954 | Gas Operator | Oct 2019 |
| 57 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 58 | Elk Production LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2011 |
| 59 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 60 | Enogex Exploration Corp | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Jun 2000 |
| 61 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 62 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 63 | EP Operating Company LP | Midland, TX 79705-5510 | Oil & Gas Operator | Mar 1993 |
| 64 | Eps Resources Corp | Englewood, CO 80111 | Oil & Gas Operator | Dec 2009 |
| 65 | Evergreen Operating Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 66 | Exit Inc | | Oil Operator | Dec 1983 |
| 67 | F & M Oil Company Inc | Pettus, TX 78146 | Oil & Gas Operator | Feb 2026 |
| 68 | F L Energy | Holladay, UT 84117-4972 | Oil & Gas Operator | Feb 2007 |
| 69 | Falcon Energy LLC | Fruita, CO 81521 | Oil & Gas Operator | Jan 2026 |
| 70 | Fidelity E&P Company | Denver, CO 80202 | Oil & Gas Operator | Feb 2016 |
| 71 | First Zone Production | Salt Lake City, UT 84102 | Oil & Gas Operator | Dec 1997 |
| 72 | Flatirons Resources LLC | Westminster, CO 80021 | Oil & Gas Operator | Dec 2022 |
| 73 | Florida Exploration Co | Aurora, CO 80014 | Oil & Gas Operator | Sep 1989 |
| 74 | Fortune Oil LTD | Salt Lake City, UT 84106 | Oil & Gas Operator | May 1987 |
| 75 | Foster Energy Group, LLC | Wolfforth, TX 79382 | Oil & Gas Operator | Dec 2025 |
| 76 | Foundation Energy Management, LLC | Addison, TX 75001 | Oil & Gas Operator | Feb 2026 |
| 77 | General Minerals Corp | Oklahoma City, OK 73105 | Oil & Gas Operator | Dec 2015 |
| 78 | Geophysical Survey Company | Grand Junction, CO 81503-1296 | Oil & Gas Operator | Jan 1996 |
| 79 | Getty Oil Company | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 80 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 81 | Graham Energy LTD | Houston, TX 77024 | Oil & Gas Operator | Mar 1994 |
| 82 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 83 | Grand Resources | Salt Lake City, UT 84115 | Oil & Gas Operator | Apr 1992 |
| 84 | Great Western Drilling Company | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 85 | Gulf Oil Corp. | Denver, CO 80201-0599 | Oil & Gas Operator | Dec 2014 |
| 86 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 87 | Hancock, Burton W | Morrison, CO 80465 | Oil & Gas Operator | Dec 2017 |
| 88 | Harper Oil Co. | Denver, CO 80217 | Oil & Gas Operator | Sep 2025 |
| 89 | Harrison, Thomas D | Park City, UT 84060-7307 | Gas Operator | Dec 1998 |
| 90 | Hunt Petroleum (Aec), Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 91 | Iacx Energy LLC | Dallas, TX 75244 | Gas Operator | Nov 2025 |
| 92 | Intrepid Oil & Gas LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2021 |
| 93 | J C Thompson Operator LLC | Greenwood, CO 80111-2919 | Oil & Gas Operator | Jul 2012 |
| 94 | Jacobs, R L Oil & Gas Co | Grand Junction, CO 81503 | Oil & Gas Operator | Oct 1986 |
| 95 | Liberty Pioneer Energy Source, Inc | Provo, UT 84604 | Oil & Gas Operator | Oct 2021 |
| 96 | Linn Bros Oil & Gas Inc | Fruita, CO 81521 | Oil & Gas Operator | Jan 2026 |
| 97 | Lone MTN Production Co | Billings, MT 59108-0965 | Oil & Gas Operator | Jul 2019 |
| 98 | Mar/Reg Oil Company | Reno, NV 89511 | Oil & Gas Operator | Dec 2025 |
| 99 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Dec 2025 |
| 100 | Master Pet & Devel Co Inc | Grand Junction, CO 81503 | Oil & Gas Operator | Jul 1999 |