| 1 | K & W Oil Company | MT Carmel, IL 62830 | Oil & Gas Operator | May 2013 |
| 2 | K N Energy Inc | Lakewood, CO 80228 | Oil & Gas Operator | Nov 2000 |
| 3 | Kachina Exploration Inc | Cheyenne, WY 82003 | Oil & Gas Operator | Jul 2000 |
| 4 | Kaiser Energy Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 1990 |
| 5 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Oct 2025 |
| 6 | Kamco Limited | Salt Lake City, UT 84105 | Oil Operator | Sep 2016 |
| 7 | Kaneb Oil & Gas | | Oil & Gas Operator | Oct 1987 |
| 8 | Kant Walter F | Lance Creek, WY 82222 | Oil & Gas Operator | Dec 2002 |
| 9 | Kara Enterprises Inc | Upton, WY 82730 | Oil Operator | Jul 2013 |
| 10 | Karlton Terry Oil Company | | Oil Operator | Jan 1991 |
| 11 | Kase Energy LLC | Roseville, MN 55113 | Oil Operator | Aug 2006 |
| 12 | Katherman Vance E | Casper, WY 82601 | Oil Operator | Dec 2004 |
| 13 | Kauffman K P Company Inc | Denver, CO 80202 | Oil & Gas Operator | Mar 1996 |
| 14 | KC Resources Inc | Snowmass VLG., CO 81615 | Oil & Gas Operator | Jun 2025 |
| 15 | KC Well Service | Big Piney, WY 83113 | Gas Operator | Jul 2025 |
| 16 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 17 | KCS Mountain Resources Inc | Manderson, WY 82432 | Oil & Gas Operator | Nov 2006 |
| 18 | Keas Production Company LLC | Estes Park, CO 80517 | Oil Operator | Jun 2025 |
| 19 | Keba Energy LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2015 |
| 20 | Kedco Management Corp | | Oil & Gas Operator | Jul 1985 |
| 21 | Keith Walker O & G Co LLC | | Oil Operator | Jun 2025 |
| 22 | Keiths Pumping Service | Douglas, WY 82633 | Oil & Gas Operator | Aug 2003 |
| 23 | Kelly Operating Company | | Oil & Gas Operator | Oct 1991 |
| 24 | Kem Ventures, LP | Katy, TX 77450 | Oil & Gas Operator | Jul 2025 |
| 25 | Kemmerer Coal Co | | Oil & Gas Operator | Dec 1981 |
| 26 | Kenai Oil & Gas Inc | | Oil & Gas Operator | Jun 1987 |
| 27 | Kennedy & Mitchell | Woodward, OK 73802 | Oil & Gas Operator | Dec 1988 |
| 28 | Kennedy George C | Upton, WY 82730 | Oil & Gas Operator | Oct 2018 |
| 29 | Kennedy Oil | Gillette, WY 82716 | Oil & Gas Operator | Aug 2025 |
| 30 | Kentex Worland LLC | Dallas, TX 75225 | Oil & Gas Operator | Aug 2025 |
| 31 | Kentta & Drwenski | Casper, WY 82602 | Oil & Gas Operator | Nov 1995 |
| 32 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | May 2025 |
| 33 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 34 | Kerr-McGee Rocky Mountain Corp | Denver, CO 80202 | Oil & Gas Operator | Jan 2007 |
| 35 | Kerry Petroleum Co Inc | Midland, TX 79708 | Oil & Gas Operator | Jun 2010 |
| 36 | Kestrel Energy Inc | Lakewood, CO 80401 | Oil & Gas Operator | Jan 2008 |
| 37 | Kewanee Oil Company | Houston, TX 77001 | Oil & Gas Operator | Aug 1978 |
| 38 | Key Production Company, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jun 2025 |
| 39 | Kiesling Oil Company | Osage, WY 82723 | Oil & Gas Operator | Oct 2007 |
| 40 | Kinder Morgan Inc | Lakewood, CO 80228 | Oil & Gas Operator | Dec 2011 |
| 41 | Kings Peak Energy LLC | Denver, CO 80264 | Oil & Gas Operator | Feb 2019 |
| 42 | Kings X Oil Company LLC | Gillette, WY 82717 | Oil Operator | Aug 2016 |
| 43 | Kirkwood W C | Casper, WY 82602 | Oil & Gas Operator | May 2005 |
| 44 | Kiska Oil & Gas Inc | Tulsa, OK 74103 | Oil Operator | Oct 2012 |
| 45 | Kissack Resources. LLC | | Oil & Gas Operator | Aug 2025 |
| 46 | Kissack Water & Oil Service Inc | Rozet, WY 82727 | Oil & Gas Operator | Aug 2025 |
| 47 | Kissinger Petroleum Corp | | Oil & Gas Operator | Nov 1983 |
| 48 | Klabzuba Oil & Gas Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 2012 |
| 49 | KLT Gas Inc | Woodlands, TX 77380 | Oil & Gas Operator | Sep 2004 |
| 50 | Kobar Corporation | Riverton, WY 82501 | Gas Operator | Dec 1996 |
| 51 | Koch Exploration Company | Houston, TX 77046 | Oil & Gas Operator | Apr 2003 |
| 52 | Koch Exploration Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 53 | Koch Production Company | Worland, WY 82401 | Oil & Gas Operator | Dec 2002 |
| 54 | Kodiak Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Sep 2020 |
| 55 | Krejci Harry L | | Oil & Gas Operator | Jul 2025 |
| 56 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |