| 701 | Kenai Oil & Gas Inc | | Oil & Gas Operator | Jun 1987 |
| 702 | Kennedy & Mitchell | Woodward, OK 73802 | Oil & Gas Operator | Dec 1988 |
| 703 | Kennedy George C | Upton, WY 82730 | Oil & Gas Operator | Oct 2018 |
| 704 | Kennedy Oil | Gillette, WY 82716 | Oil & Gas Operator | Jan 2026 |
| 705 | Kentex Worland LLC | Dallas, TX 75225 | Oil & Gas Operator | Sep 2025 |
| 706 | Kentex Worland Operating Co LLC | | Oil & Gas Operator | Feb 2026 |
| 707 | Kentta & Drwenski | Casper, WY 82602 | Oil & Gas Operator | Nov 1995 |
| 708 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Feb 2026 |
| 709 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Apr 2026 |
| 710 | Kerr-McGee Rocky Mountain Corp | Denver, CO 80202 | Oil & Gas Operator | Jan 2007 |
| 711 | Kerry Petroleum Co Inc | Midland, TX 79708 | Oil & Gas Operator | Jun 2010 |
| 712 | Kestrel Energy Inc | Lakewood, CO 80401 | Oil & Gas Operator | Jan 2008 |
| 713 | Kewanee Oil Company | Houston, TX 77001 | Oil & Gas Operator | Aug 1978 |
| 714 | Key Production Company, Inc. | Longview, TX 75606 | Oil & Gas Operator | Feb 2026 |
| 715 | Kiesling Oil Company | Osage, WY 82723 | Oil & Gas Operator | Oct 2007 |
| 716 | Kinder Morgan Inc | Lakewood, CO 80228 | Oil & Gas Operator | Dec 2011 |
| 717 | Kings Peak Energy LLC | Denver, CO 80264 | Oil & Gas Operator | Feb 2019 |
| 718 | Kings X Oil Company LLC | Gillette, WY 82717 | Oil Operator | Aug 2016 |
| 719 | Kirkwood W C | Casper, WY 82602 | Oil & Gas Operator | May 2005 |
| 720 | Kiska Oil & Gas Inc | Tulsa, OK 74103 | Oil Operator | Oct 2012 |
| 721 | Kissack Resources. LLC | | Oil & Gas Operator | Jan 2026 |
| 722 | Kissack Water & Oil Service Inc | Rozet, WY 82727 | Oil & Gas Operator | Feb 2026 |
| 723 | Kissinger Petroleum Corp | | Oil & Gas Operator | Nov 1983 |
| 724 | Klabzuba Oil & Gas Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 2012 |
| 725 | Kobar Corporation | Riverton, WY 82501 | Gas Operator | Dec 1996 |
| 726 | Koch Exploration Company | Houston, TX 77046 | Oil & Gas Operator | Apr 2003 |
| 727 | Koch Exploration Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2019 |
| 728 | Koch Production Company | Worland, WY 82401 | Oil & Gas Operator | Dec 2002 |
| 729 | Kodiak Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Sep 2020 |
| 730 | Krejci Harry L | | Oil & Gas Operator | Jan 2026 |
| 731 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2026 |
| 732 | L & B Oil Company Inc | Dallas, TX 75225 | Oil & Gas Operator | Mar 2025 |
| 733 | L & J Operating Inc | Gillette, WY 82718 | Oil & Gas Operator | Aug 2016 |
| 734 | L & R Drilling Company | Belle Fourche, SD 57717 | Oil & Gas Operator | Dec 1999 |
| 735 | L B Industries Inc | Englewood, CO 80112 | Oil & Gas Operator | Jun 2003 |
| 736 | L R Company | Casper, WY 82602 | Oil & Gas Operator | Sep 2007 |
| 737 | La Prele Exploration | | Oil & Gas Operator | Oct 1979 |
| 738 | Labarge Minerals Inc | Labarge, WY 83123 | Oil & Gas Operator | Jan 2020 |
| 739 | Ladd & Lukowicz | | Oil & Gas Operator | May 1983 |
| 740 | Lagniappe Interest Inc | Evergreen, CO 80439 | Oil & Gas Operator | Jun 2006 |
| 741 | Laguna Petroleum Company | Casper, WY 82601 | Oil & Gas Operator | Dec 1982 |
| 742 | Lakota Partnership | Denver, CO 80202 | Oil Operator | Oct 1990 |
| 743 | Lance Oil & Gas Company Inc | Kirtland, NM 87417 | Oil & Gas Operator | Mar 2013 |
| 744 | Langley Energy | Euless, TX 76040 | Gas Operator | Jan 2016 |
| 745 | Lappin Oil LLC | Douglas, WY 82633 | Oil & Gas Operator | Mar 2026 |
| 746 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | Apr 2026 |
| 747 | Lasmo Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2024 |
| 748 | Lawson Oil Company | Buckeye, AR 85326 | Oil Operator | Mar 1996 |
| 749 | Lear Petroleum Exploration | | Oil & Gas Operator | Jul 2013 |
| 750 | Leclair-Westwood Inc | | Oil & Gas Operator | Mar 1982 |
| 751 | Leeman Don J | Oklahoma City, OK 73112 | Oil & Gas Operator | Sep 1998 |
| 752 | Legacy Energy Inc | Carpinteria, CA 93013 | Oil & Gas Operator | Jun 2012 |
| 753 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Apr 2026 |
| 754 | Levinson Partners Corporation | Denver, CO 80202 | Oil & Gas Operator | Jul 1995 |
| 755 | Lewis & Clark Exploration | | Oil Operator | Feb 1989 |
| 756 | Lewis Yale H | | Oil & Gas Operator | Aug 1986 |
| 757 | Lexicon Resources Corporation | | Oil & Gas Operator | Apr 1986 |
| 758 | Liberty Production Co | Houston, TX 77002 | Oil & Gas Operator | Nov 1994 |
| 759 | Liberty Resources Management Co LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2026 |
| 760 | Lilis Energy Inc | Denver, CO 80203 | Oil & Gas Operator | Aug 2017 |
| 761 | Lincero LLC | Sinclair, WY 82334 | Oil Operator | Feb 2026 |
| 762 | Linn Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 763 | Lissolo J W | Yuma, AZ 85365 | Oil & Gas Operator | Feb 2017 |
| 764 | Lissolo Timothy C | Newcastle, WY 82701 | Oil Operator | Jan 2026 |
| 765 | Llosu Corporation | Rawlins, WY 82301 | Oil & Gas Operator | Mar 2002 |
| 766 | Loco | Casper, WY 82602 | Oil & Gas Operator | Jul 2022 |
| 767 | Lodestone Operating | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 768 | Loil Oil LLC | Golden, CO 80402 | Oil & Gas Operator | Feb 2026 |
| 769 | Lone Star Land And Energy II LLC | Dallas, TX 75214 | Oil & Gas Operator | Jan 2020 |
| 770 | Long Beach Oil Development Co | Glendale, CA 91203 | Oil & Gas Operator | Jun 2004 |
| 771 | Long Trust The | Kilgore, TX 75663 | Oil & Gas Operator | Aug 2008 |
| 772 | Longs Peak Resources LLC | Houston, TX 77019 | Oil & Gas Operator | Feb 2026 |
| 773 | Loral Operating LLC | Sheridan, WY 82801 | Gas Operator | Apr 2011 |
| 774 | Louisiana Land & Exploration Co. | Houston, TX 77210 | Oil & Gas Operator | Sep 2013 |
| 775 | Loundagin N B | Casper, WY 82602 | Oil & Gas Operator | Sep 2015 |
| 776 | Low D J | Littleton, CO 80127 | Oil Operator | Dec 1999 |
| 777 | Lowry Exploration Inc | Tulsa, OK 74119 | Oil & Gas Operator | Jan 2026 |
| 778 | Luff Exploration | Denver, CO 80203 | Oil & Gas Operator | Dec 2006 |
| 779 | Lusk Operating LLC | Denver, CO 80202 | Oil Operator | Jun 2017 |
| 780 | Lyco Operating Company | Dallas, TX 75206 | Gas Operator | Dec 1997 |
| 781 | M & C Oil Inc | Indianola, NE 68034 | Oil & Gas Operator | Nov 2013 |
| 782 | M & G Oil And Gas Inc | Llabarge, WY 83123 | Oil & Gas Operator | Apr 2023 |
| 783 | M & K Oil Company LLC | Gillette, WY 82716 | Oil & Gas Operator | Feb 2026 |
| 784 | M & K Oil Operations | | Oil & Gas Operator | Sep 1994 |
| 785 | M G Production Co | Rock Springs, WY 82901 | Oil Operator | Dec 1999 |
| 786 | M K M Oil Company | Casper, WY 82602 | Oil & Gas Operator | Jun 1996 |
| 787 | M W Petroleum Company | Houston, TX 77056 | Oil & Gas Operator | Dec 1995 |
| 788 | M-3 Industries | Casper, WY 82602 | Oil & Gas Operator | Dec 2025 |
| 789 | M2S Oil LLC | | Oil Operator | Jan 2026 |
| 790 | Mack Energy Corporation | Artesia, NM 88211 | Oil & Gas Operator | Feb 2026 |
| 791 | Macum Energy Inc | Billings, MT 59104 | Oil & Gas Operator | Aug 2021 |
| 792 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 793 | Maha Energy Us Inc | | Oil Operator | Nov 2023 |
| 794 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 795 | Majestic Petroleum Operations Inc | Story, WY 82842 | Gas Operator | Mar 2007 |
| 796 | Mak-J Energy Wyoming LLC | Denver, CO 80620 | Oil & Gas Operator | Nov 2012 |
| 797 | Mallon Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2005 |
| 798 | Manewal Bradley Oil Company | Newcastle, WY 82701 | Oil & Gas Operator | Aug 2013 |
| 799 | Manx Oil Corporation | Casper, WY 82601 | Oil & Gas Operator | Jun 2010 |
| 800 | Mapco Oil Company | | Oil & Gas Operator | Jan 1985 |