| 1 | Afe Management Limited | Concord, Ontario, L4K 4G4 | Oil & Gas Operator | Sep 1987 |
| 2 | Albritton Resources Inc | Dallas, TX 75206 | Oil & Gas Operator | Feb 2001 |
| 3 | Alta Energy Corporation | Midland, TX 79701 | Oil & Gas Operator | Apr 1995 |
| 4 | Altamont Energy Operating LLC | Greenwood VIlliage, CO 80111 | Oil & Gas Operator | Sep 2024 |
| 5 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 6 | Amtech Energy Inc | Plymouth, IL 62367-1016 | Oil & Gas Operator | Dec 2021 |
| 7 | Anr Limited Inc/Coastal | Houston, TX 770460995 | Oil & Gas Operator | Dec 1987 |
| 8 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 9 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 10 | Appaloosa Operating Company LLC | The Woodlands, TX 77387 | Oil & Gas Operator | Apr 2019 |
| 11 | Asamera Oil Us Inc | Denver, CO 80201 | Oil & Gas Operator | Jul 1985 |
| 12 | Axia Energy II LLC | HGHLNDS Ranch, CO 80129 | Oil & Gas Operator | Jan 2020 |
| 13 | Badger Oil Corporation | Lafayette, LA 70505 | Oil & Gas Operator | Nov 2011 |
| 14 | Badlands Production Company | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Sep 2018 |
| 15 | Barrett Resources Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 16 | Berry Petroleum Company | Denver, CO 80202 | Oil & Gas Operator | Feb 2014 |
| 17 | Berry Petroleum Company LLC | Bakersfield, CA 93311 | Oil & Gas Operator | Aug 2025 |
| 18 | Bill Barrett Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 19 | Birch Corporation | Denver, CO 80217 | Oil & Gas Operator | Dec 1989 |
| 20 | Bow Valley Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1996 |
| 21 | Brinkerhoff Drilling Co | | Oil & Gas Operator | Jul 1975 |
| 22 | Burton/Hawks Inc | Casper, WY 82602 | Oil & Gas Operator | Sep 1993 |
| 23 | Bwab Incorporated | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 24 | California Oil Co | | Oil & Gas Operator | Aug 1965 |
| 25 | Campbell, G S | Park City, UT 84060 | Oil & Gas Operator | Apr 1991 |
| 26 | Carter Oil Co | | Oil & Gas Operator | Dec 2013 |
| 27 | Celsius Energy Company | Denver, CO 80202-1558 | Oil & Gas Operator | Mar 2000 |
| 28 | Chandler & Associated Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 1999 |
| 29 | Chevron Oil Company | | Oil & Gas Operator | Dec 1983 |
| 30 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 31 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 32 | Cochrane Resources Inc | Roosevelt, UT 84066 | Oil & Gas Operator | Aug 2025 |
| 33 | Coltharp, Edward H | | Oil & Gas Operator | Dec 1970 |
| 34 | Columbia Gas Development | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 35 | Continental Oil Co. | Durango, CO 81301 | Oil & Gas Operator | Dec 1983 |
| 36 | Coors Energy | Golden, CO 80402-0467 | Oil & Gas Operator | Sep 1992 |
| 37 | Cotton Petroleum Corp/Apc | Denver, CO 80203-4549 | Oil & Gas Operator | Nov 1990 |
| 38 | Crescent Point Energy Us Corp | Denver, CO 80202 | Oil & Gas Operator | Apr 2024 |
| 39 | CSX Oil & Gas Corporation | Houston, TX 77210-4326 | Oil & Gas Operator | Mar 1993 |
| 40 | Dalen Resources Oil & Gas | Dallas, TX 75206-3922 | Oil & Gas Operator | Jan 1996 |
| 41 | Devon Energy Operating Corp | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2013 |
| 42 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 43 | Diamond Shamrock Corp | Amarillo, TX 79105 | Oil & Gas Operator | Jan 1987 |
| 44 | Diamond Shamrock Expl | Dallas, TX 75201 | Oil & Gas Operator | May 1987 |
| 45 | DKM Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Sep 2011 |
| 46 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 47 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 48 | Energetics Inc | Englewood, CO 80155 | Oil & Gas Operator | Aug 1985 |
| 49 | Energy Reserves Group | Houston, TX 770563020 | Oil & Gas Operator | Apr 1996 |
| 50 | Enerplus Resources USA Corporation | Denver, CO 80202 | Oil & Gas Operator | Aug 2025 |
| 51 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 52 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 53 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 54 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 55 | EP Operating Company LP | Midland, TX 79705-5510 | Oil & Gas Operator | Mar 1993 |
| 56 | Eps Resources Corp | Englewood, CO 80111 | Oil & Gas Operator | Dec 2009 |
| 57 | Equitable Resources Energy | Houston, TX 77056-2742 | Oil & Gas Operator | Sep 1997 |
| 58 | Evertson Oil Company Inc | Kimball, NE 69145 | Oil & Gas Operator | Sep 2001 |
| 59 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 60 | Fiml Natural Resources LLC (FNR) | Denver, CO 80202-4438 | Oil & Gas Operator | Jul 2014 |
| 61 | Finley Resources Inc | Fort Worth, TX 76113 | Oil & Gas Operator | Oct 2025 |
| 62 | First Energy Corporation | | Oil & Gas Operator | Jun 1993 |
| 63 | Flying Diamond Oil Corp | | Oil & Gas Operator | Dec 1983 |
| 64 | Flying J Inc | Roosevelt, UT 84066 | Oil & Gas Operator | Jul 1995 |
| 65 | Flying J Oil & Gas Inc | North Salt Lake, UT 84054 | Oil & Gas Operator | Dec 2009 |
| 66 | Fourpoint Resources, LLC | Denver, CO 80206 | Oil & Gas Operator | Jul 2025 |
| 67 | Fuel Explor Inc (Fuelex) | | Oil & Gas Operator | Sep 1998 |
| 68 | Gas & Oil Management Inc | Englewood, CO 80112 | Oil & Gas Operator | Dec 1974 |
| 69 | Gas Producing Enterprises | Houston, TX 77046 | Oil & Gas Operator | Dec 1983 |
| 70 | Gasco Production Company | Denver, CO 80237 | Oil & Gas Operator | Dec 2015 |
| 71 | Gavilan Petroleum Inc | Park City, UT 84060 | Oil & Gas Operator | Dec 2006 |
| 72 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 73 | Graham Energy LTD | Houston, TX 77024 | Oil & Gas Operator | Mar 1994 |
| 74 | Graham Resources Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1988 |
| 75 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 76 | Gulf Energy Corporation | Denver, CO 80237 | Oil & Gas Operator | Jun 1987 |
| 77 | Gulf Oil Corp. | Denver, CO 80201-0599 | Oil & Gas Operator | Dec 2014 |
| 78 | GW Petroleum Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 1993 |
| 79 | Hadden, Pennell & Rohret | Lakewood, CO 80228 | Oil Operator | Nov 1994 |
| 80 | Harvest (Us) Holdings, Inc | Houston, TX 77077 | Oil & Gas Operator | Apr 2011 |
| 81 | Held By Production, Inc. | Houston, TX 77251 | Oil & Gas Operator | May 1996 |
| 82 | Homeland Gas & Oil, Inc | Roosevelt, UT 84066-1574 | Oil & Gas Operator | Jun 2025 |
| 83 | Hot Rod Oil | Vernal, UT 84078 | Oil & Gas Operator | Jun 2025 |
| 84 | Humble Oil & Refining Co. | Houston, TX 77252 | Oil & Gas Operator | Jan 2000 |
| 85 | Husky Oil Company | Cody, WY 82414 | Oil & Gas Operator | Dec 1984 |
| 86 | Inland Production Company | Vernal, UT 84079 | Oil & Gas Operator | Dec 2004 |
| 87 | Intercoast Oil And Gas Company | Tulsa, OK 74136 | Oil & Gas Operator | Jun 1997 |
| 88 | Interline Resources Corp | Casper, WY 82601 | Oil & Gas Operator | Oct 2009 |
| 89 | Ironwood Exploration Inc | | Oil & Gas Operator | Mar 1995 |
| 90 | J. M. Huber Corp. | Houston, TX 77079 | Oil & Gas Operator | Sep 2004 |
| 91 | Javelin Energy Partners Management, LLC | Irving, TX 75038 | Oil & Gas Operator | Oct 2025 |
| 92 | Koch Exploration Company | Houston, TX 77046 | Oil & Gas Operator | Apr 2003 |
| 93 | Linmar Energy Corporation | Denver, CO 80237 | Oil & Gas Operator | Oct 1987 |
| 94 | Linmar Petroleum Company | Denver, CO 80237 | Oil & Gas Operator | Oct 1995 |
| 95 | Linn Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 96 | Linn Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2017 |
| 97 | Lomax Exploration Company | Roosevelt, UT 84066 | Oil & Gas Operator | Jun 1995 |
| 98 | Mapco Inc | Billings, MT 59102 | Oil & Gas Operator | Dec 1983 |
| 99 | Mapco Oil & Gas Company | Tulsa, OK 74101-2115 | Oil & Gas Operator | Jan 1985 |
| 100 | Mapco Production Co | Billings, MT 59102 | Oil & Gas Operator | Apr 1994 |