| 1 | Aec Oil & Gas USA Inc | Denver, CO 80202 | Oil & Gas Operator | May 2004 |
| 2 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 3 | Antero Resources Piceance LLC | | Oil & Gas Operator | Dec 2012 |
| 4 | Augustus Energy Partners LLC | Billings, MT 59102 | Oil & Gas Operator | Feb 2014 |
| 5 | Ballard Petroleum LLC | Billings, MT 59102-5406 | Oil & Gas Operator | Apr 2014 |
| 6 | Barrett Corporation* Bill | | Oil & Gas Operator | Jan 2024 |
| 7 | Barrett Resources Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 8 | Beartooth Oil & Gas Company | Billings, MT 59103 | Oil & Gas Operator | Feb 2024 |
| 9 | Berry Petroleum Company LLC | Bakersfield, CA 93311 | Oil & Gas Operator | Feb 2024 |
| 10 | Black Diamond Minerals LLC | | Oil & Gas Operator | Jun 2014 |
| 11 | Black Hills Plateau Production LLC | | Oil & Gas Operator | May 2018 |
| 12 | Bonneville Fuels Corp | Denver, CO 80290 | Oil & Gas Operator | Jun 2002 |
| 13 | Caerus Piceance LLC | | Oil & Gas Operator | Feb 2024 |
| 14 | Caerus Washco LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2024 |
| 15 | Calpine Natural Gas L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2006 |
| 16 | Carbon Energy Corporation (USA) | Denver, CO 80290 | Oil & Gas Operator | Jul 2004 |
| 17 | CDX Rockies LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2005 |
| 18 | Celsius Energy Company | Denver, CO 80202-1558 | Oil & Gas Operator | Mar 2000 |
| 19 | Chandler & Associates LLC | | Oil & Gas Operator | Jul 2001 |
| 20 | Chevron Midcontinent, L.P. | Midland, TX 79706 | Oil & Gas Operator | Apr 2024 |
| 21 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Apr 2024 |
| 22 | Coachman Energy Operating Company LLC | Englewood, CO 80111 | Oil & Gas Operator | Aug 2018 |
| 23 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 24 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2024 |
| 25 | CPX Piceance Holdings LLC | | Oil & Gas Operator | Feb 2024 |
| 26 | D & G Roustabout Service | | Oil & Gas Operator | Jan 2024 |
| 27 | Daniels Petroleum Co | Denver, CO 80202 | Oil & Gas Operator | Mar 2003 |
| 28 | Dejour Energy (USA) Corporation | | Oil & Gas Operator | Jun 2014 |
| 29 | Diamond Oil And Gas, Inc. | Kalamazoo, MI 49001 | Oil & Gas Operator | Apr 2024 |
| 30 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 31 | EP Energy Management LLC | | Oil & Gas Operator | Jun 2006 |
| 32 | Evergreen Operating Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 33 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Apr 2024 |
| 34 | Fees Jr And Son Oil & Gas* Walter S | | Oil & Gas Operator | Jan 2024 |
| 35 | Foundation Energy Management, LLC | Addison, TX 75001 | Oil & Gas Operator | Apr 2024 |
| 36 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2023 |
| 37 | Hec Petroleum, Inc | Midland, TX 79705 | Oil & Gas Operator | Mar 2006 |
| 38 | HRM Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2015 |
| 39 | Jelco G V Inc | | Gas Operator | Dec 2005 |
| 40 | KLT Gas Inc | Woodlands, TX 77380 | Oil & Gas Operator | Sep 2004 |
| 41 | Laramie Energy II LLC | Denver, CO 80202 | Oil & Gas Operator | Sep 2015 |
| 42 | Laramie Energy LLC | | Oil & Gas Operator | Aug 2013 |
| 43 | Lasso Oil & Gas LLC | | Oil & Gas Operator | Jul 2022 |
| 44 | Linn Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 45 | Locin Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 46 | Lone Mountain Production Company | | Oil & Gas Operator | Jan 2016 |
| 47 | Maralex Resources Inc | Ignacio, CO 81137 | Oil & Gas Operator | Feb 2024 |
| 48 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Feb 2024 |
| 49 | Merrion Oil & Gas Corp | Farmington, NM 87401 | Oil & Gas Operator | Feb 2024 |
| 50 | Mesa Hydrocarbons LLC | | Oil & Gas Operator | Sep 2003 |
| 51 | MRD Operating LLC | | Oil & Gas Operator | Dec 2016 |
| 52 | Mustang Resources LLC | Houston, TX 77256 | Oil & Gas Operator | Feb 2024 |
| 53 | National Fuel Corporation | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Feb 2024 |
| 54 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Apr 2024 |
| 55 | Noble Energy Production Inc | Houston, TX 77067 | Oil & Gas Operator | Apr 2024 |
| 56 | Nonsuch Natural Gas Inc | Naples, FL 34108 | Oil & Gas Operator | Feb 2024 |
| 57 | Northstar Gas Company Inc | | Oil & Gas Operator | Jan 2016 |
| 58 | Orion Energy Partners LP | Denver, CO 80202 | Oil & Gas Operator | Nov 2010 |
| 59 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Apr 2024 |
| 60 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | Apr 2024 |
| 61 | PDC Energy Inc | Denver, CO 80203 | Oil & Gas Operator | Jan 2024 |
| 62 | Petro Mex Resources | | Oil & Gas Operator | Feb 2024 |
| 63 | Petrogulf Corporation | Denver, CO 80202 | Oil & Gas Operator | Apr 2024 |
| 64 | Piceance Energy LLC | | Oil & Gas Operator | Jan 2024 |
| 65 | Piceance Operating Company LLC | | Gas Operator | Oct 2006 |
| 66 | Pioneer Natural Resources USA Inc | Irving, TX 75039 | Oil & Gas Operator | Dec 2023 |
| 67 | Plains Exploration & Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Jul 2013 |
| 68 | Presco Inc | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2020 |
| 69 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Dec 2023 |
| 70 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 71 | Retamco Operating Inc | Red Lodge, MT 59068-0790 | Oil & Gas Operator | Jan 2024 |
| 72 | San Marco Petroleum Inc | Denver, CO 80293 | Oil & Gas Operator | Jan 2024 |
| 73 | Slate River Resources LLC | Denver, CO 80293 | Oil & Gas Operator | Apr 2008 |
| 74 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 75 | Strachan Exploration Inc | Englewood, CO 80112 | Oil & Gas Operator | Feb 2024 |
| 76 | Swevco-Sabw LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2024 |
| 77 | Timberline Energy Inc | Franklin, PA 16323-0269 | Oil & Gas Operator | Jun 2018 |
| 78 | Tom Brown Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2004 |
| 79 | Twin Arrow Inc | Rangely, CO 81648 | Oil & Gas Operator | Sep 2009 |
| 80 | U S Department Of Energy | | Oil & Gas Operator | Apr 1999 |
| 81 | Ursa Operating Company LLC | Denver, CO 80265 | Oil & Gas Operator | Dec 2020 |
| 82 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Feb 2021 |
| 83 | Vaquero Energy Inc | Bakersfield, CA 93309 | Oil & Gas Operator | May 2023 |
| 84 | Venoco, Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 85 | Vision Energy LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2024 |
| 86 | Vitruvian Exploration LLC | The Woodlands, TX 77380 | Oil & Gas Operator | May 2016 |
| 87 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 88 | Windsor Energy Group LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2021 |
| 89 | WPX Energy Rocky Mountain LLC | Tulsa, OK 74101 | Oil & Gas Operator | Feb 2024 |