| 701 | Casa Operations | Borger, TX 79007 | Oil & Gas Operator | Jul 2026 |
| 702 | Cascade Oil (Dba) | Ness City, KS 67560 | Oil Operator | Mar 1998 |
| 703 | Cascade Oil Comp | | Oil & Gas Operator | Dec 1994 |
| 704 | Cascade Petroleum Corporation | Quitman, TX 75783 | Oil & Gas Operator | Mar 2002 |
| 705 | Cascade Petroleum Inc | North Canton, OH 44720-4244 | Oil & Gas Operator | Dec 1992 |
| 706 | Cascade Resources LLC | Edmond, OK 73083 | Oil & Gas Operator | May 2026 |
| 707 | Case Brothers Inc. | Limestone, NY 14753 | Oil & Gas Operator | Dec 2025 |
| 708 | Case Drilling Company | Philpot, KY 42366 | Oil Operator | Dec 2020 |
| 709 | Case Oil | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2026 |
| 710 | Case Oil & Gas I | | Oil & Gas Operator | Apr 1992 |
| 711 | Case Resources, LLC | Graham, TX 76450 | Oil & Gas Operator | Jul 2026 |
| 712 | Case Sales Company Inc | Tonkawa, OK 74653-0040 | Oil & Gas Operator | Apr 2026 |
| 713 | Case'S Used Equipment | | Oil & Gas Operator | Mar 2026 |
| 714 | Case, C. W. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2026 |
| 715 | Casebeer, Inc. | McPherson, KS 67460 | Oil Operator | Mar 2026 |
| 716 | Casella Charles J | Avonmore, PA 15618-1028 | Oil & Gas Operator | Dec 2015 |
| 717 | Casex Company | | Oil & Gas Operator | Dec 2007 |
| 718 | Casey Musgrove Oil Company Inc | Ponca City, OK 74602 | Oil & Gas Operator | May 2026 |
| 719 | Casey, Carl D | | Oil Operator | Sep 2024 |
| 720 | Casey, W. J. | Fairfield, TX 75840 | Oil & Gas Operator | Jul 2026 |
| 721 | Cash Flow Oil | | Oil Operator | Jul 2003 |
| 722 | Cashco Energy Corporation | | Oil & Gas Operator | Feb 1982 |
| 723 | Cashco Oil Company | Houston, TX 77024 | Oil & Gas Operator | Aug 2003 |
| 724 | Cashco, L.L.C. | Houston, TX 77024 | Oil & Gas Operator | Jul 1999 |
| 725 | Cashion, Lyle, Company | Brandon, MS 39047 | Oil & Gas Operator | May 2008 |
| 726 | Casias Oil Well Service, Inc. | San Antonio, TX 78232 | Oil & Gas Operator | Jul 2020 |
| 727 | Casillas Operating LLC | Tulsa, OK 74103-4060 | Oil & Gas Operator | Apr 2026 |
| 728 | Casillas Petroleum Corp | Satanta, KS 67870 | Oil & Gas Operator | May 2026 |
| 729 | Casino Petroleum | | Oil Operator | Dec 1996 |
| 730 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Jul 2026 |
| 731 | Cason William J | Santee, CA 92071-2765 | Oil Operator | Sep 2019 |
| 732 | Caspen Oil, Inc. | Lakewood, CO 80226 | Oil & Gas Operator | Jul 1993 |
| 733 | Caspen Operating Company | Somerset, TX 78069 | Oil & Gas Operator | Mar 2008 |
| 734 | Casper Oil & Gas | Bandera, TX 78003 | Oil & Gas Operator | Oct 2002 |
| 735 | Cass Energy Corp | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 736 | Cass Energy LLC | MT Vernon, TX 75457 | Oil Operator | Jul 2026 |
| 737 | Cassadaga Valley Central School | Sinclairville, NY 14782 | Gas Operator | Dec 2025 |
| 738 | Casselman Charles Jack | Okmulgee, OK 74447-4265 | Oil & Gas Operator | Apr 2020 |
| 739 | Casselman Leases LLC | Morris, OK 74445-2509 | Oil & Gas Operator | Apr 2026 |
| 740 | Casselman Ronald H | Morris, OK 74445 | Oil & Gas Operator | Apr 2026 |
| 741 | Casselman-Sheely | Emporia, KS 66801 | Oil & Gas Operator | Oct 2021 |
| 742 | Cassidy Jr John | Stroud, OK 74079-0200 | Oil & Gas Operator | Nov 2014 |
| 743 | Cassity Company | Wichita Falls, TX 76309 | Oil & Gas Operator | Jul 2013 |
| 744 | Cassius Congdon Legacy, LLC | West Clarksville, NY 14786 | Oil & Gas Operator | Dec 2025 |
| 745 | Casteel, Hoyt F. | Graham, TX 76450 | Oil & Gas Operator | Nov 2001 |
| 746 | Castella Inc | Bartlesville, OK 74003-3712 | Oil & Gas Operator | Apr 2026 |
| 747 | Castelli Exploration Inc | Oklahoma City, OK 73162 | Oil & Gas Operator | Apr 2026 |
| 748 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2026 |
| 749 | Castillo Oil Company LLC | Luling, TX 78648 | Oil & Gas Operator | Jul 2026 |
| 750 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 751 | Castle Gas Company Inc | Pittsburgh, PA 15236-2466 | Oil & Gas Operator | Dec 2007 |
| 752 | Castle Gas Corporation | San Angelo, TX 76902 | Oil & Gas Operator | Oct 2014 |
| 753 | Castle Minerals | | Oil & Gas Operator | Dec 2018 |
| 754 | Castle Operating LLC | Oklahoma City, OK 73114-7444 | Oil & Gas Operator | Apr 2026 |
| 755 | Castle Production Company | Henderson, TX 75652 | Oil & Gas Operator | May 1997 |
| 756 | Castle Resources | | Oil Operator | Jul 2002 |
| 757 | Castle Resources, Inc. | Russell, KS 67665 | Oil & Gas Operator | Mar 2026 |
| 758 | Castle Rock Oil LLC | | Oil Operator | May 2026 |
| 759 | Castle-Rock Prod | | Oil Operator | Mar 1992 |
| 760 | Castlerock Ef Operating LLC | San Antonio, TX 78232 | Oil & Gas Operator | Jul 2026 |
| 761 | Castlerock Oil Company, Inc. | Addison, TX 75001 | Oil & Gas Operator | Feb 2006 |
| 762 | Castlerock Operating, LLC | San Antonio, TX 78232 | Oil & Gas Operator | Dec 2020 |
| 763 | Castlerock Resources Inc | Oklahoma City, OK 73116-3710 | Oil & Gas Operator | Jul 2020 |
| 764 | Castor Exploration, Inc. | | Oil & Gas Operator | Dec 1991 |
| 765 | Castor Production, L.L.C. | | Oil Operator | Dec 2024 |
| 766 | Caswell Bros. Oil Co. | Bowie, TX 76230 | Oil & Gas Operator | Jul 2026 |
| 767 | Cat Canyon Resources LLC | | Oil & Gas Operator | May 2026 |
| 768 | Cat Creek Holdings LLC | Winnett, MT 59087 | Oil Operator | May 2026 |
| 769 | Cat Energy, LLC | Galva, KS 67443 | Oil Operator | Aug 2008 |
| 770 | Cat Oil | Byron, WY 82412 | Oil Operator | May 2001 |
| 771 | Cat-Oil Inc. | | Oil Operator | Nov 2015 |
| 772 | Catalyst Energy Inc | Pittsburgh, PA 15218 | Oil & Gas Operator | Apr 2026 |
| 773 | Catamount Energy Partners LLC | Denver, CO 80202 | Gas Operator | Jun 2026 |
| 774 | Catamount Resources, Inc. | Grafton, WV 26354-0000 | Gas Operator | Dec 2009 |
| 775 | Catarina Petroleum L. C. | Dallas, TX 75228 | Oil & Gas Operator | Jun 2008 |
| 776 | Catena Resources Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2022 |
| 777 | Cates Betty J | Tulsa, OK 74112 | Oil & Gas Operator | Nov 2016 |
| 778 | Catfish Minerals LLC | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 779 | Catfish Oil | | Oil Operator | Mar 2026 |
| 780 | Cather Rogers Barnes & Cree | | Oil & Gas Operator | Dec 2009 |
| 781 | Cather, Barnes & Cree | | Oil & Gas Operator | Dec 2009 |
| 782 | Cather-Herley Oil Company | | Oil & Gas Operator | May 2026 |
| 783 | Cathexis Oil & Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2014 |
| 784 | Cathey Oil, Inc. | | Oil & Gas Operator | Aug 2009 |
| 785 | Cathey Petroleum Company, Inc. | Big Spring, TX 79720 | Oil & Gas Operator | Apr 2008 |
| 786 | Cathey Production Company | Ryan, OK 73565-0485 | Oil Operator | Dec 2010 |
| 787 | Caths Oil & Gas | Midland, TX 79706 | Oil & Gas Operator | Jul 2026 |
| 788 | Catlett & Ferguson-Carl O & G | | Oil & Gas Operator | Jun 1978 |
| 789 | Catlin Drilling Company | Iowa Park, TX 76367 | Oil & Gas Operator | Aug 2003 |
| 790 | Catlin, Carl | Jacksboro, TX 76458 | Oil & Gas Operator | Mar 2008 |
| 791 | Catlin, Cecil | Iowa Park, TX 76367 | Oil & Gas Operator | Dec 1995 |
| 792 | Catlin, Cecil, Oil Co. | Iowa Park, TX 76367 | Oil & Gas Operator | Jun 2000 |
| 793 | Catlin, Delbert | Iowa Park, TX 76367 | Oil & Gas Operator | Jul 2026 |
| 794 | Catlin, Randy | Iowa Park, TX 76367 | Oil Operator | Jul 2026 |
| 795 | Catoilan Corporation | Midland, TX 79702 | Oil & Gas Operator | Jul 2026 |
| 796 | Catron Oil Div - | | Oil Operator | Aug 1989 |
| 797 | Catron Oil Division | | Oil Operator | Feb 2000 |
| 798 | Catron, Jeffery V | | Oil Operator | Dec 2024 |
| 799 | Catt Drilling Co. | Holyrood, KS 67450 | Oil Operator | Aug 1989 |
| 800 | Cattlemans Oil O | | Oil Operator | Nov 1995 |