| 701 | Carter-Waters Corp. | | Oil Operator | Dec 1988 |
| 702 | Cartex Production | Pampa, TX 79066 | Oil & Gas Operator | Oct 2025 |
| 703 | Cartex Production Corp. | Pampa, TX 79066 | Oil & Gas Operator | Nov 2000 |
| 704 | Cartledge & Cartledge Oil Company Inc | Kiefer, OK 74041 | Oil & Gas Operator | Jun 2025 |
| 705 | Cartledge Energy LLC | Sapulpa, OK 74066-6623 | Oil & Gas Operator | Jul 2025 |
| 706 | Caruthers Operating Co., Inc. | | Oil & Gas Operator | Jul 2010 |
| 707 | Caruthers Producing Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2019 |
| 708 | Carver Harry | Oklahoma City, OK 73120 | Oil & Gas Operator | Nov 2000 |
| 709 | Cary Oil & Gas, Inc | Decatur, TX 76234 | Oil & Gas Operator | Oct 2025 |
| 710 | Casa Grande Exploration Company | Casa Grande, AZ 85194 | Oil & Gas Operator | Jun 2025 |
| 711 | Casa Oil And Gas Company | George West, TX 78022 | Gas Operator | Sep 2005 |
| 712 | Casa Operations | Borger, TX 79007 | Oil & Gas Operator | Oct 2025 |
| 713 | Cascade Oil (Dba) | Ness City, KS 67560 | Oil Operator | Mar 1998 |
| 714 | Cascade Oil And Gas, Inc | | Oil & Gas Operator | Jun 2005 |
| 715 | Cascade Oil Comp | | Oil & Gas Operator | Dec 1994 |
| 716 | Cascade Petroleum Corporation | Quitman, TX 75783 | Oil & Gas Operator | Mar 2002 |
| 717 | Cascade Petroleum Inc | North Canton, OH 44720-4244 | Oil & Gas Operator | Dec 1992 |
| 718 | Cascade Petroleum LLC | | Oil & Gas Operator | Nov 2015 |
| 719 | Cascade Resources LLC | Edmond, OK 73083 | Oil & Gas Operator | Aug 2025 |
| 720 | Casco Energy, Inc. | Denison, TX 75020 | Oil & Gas Operator | May 1996 |
| 721 | Case Brothers Inc. | Limestone, NY 14753 | Oil & Gas Operator | Dec 2024 |
| 722 | Case Drilling Company | Philpot, KY 42366 | Oil Operator | Dec 2019 |
| 723 | Case Oil | Burkburnett, TX 76354 | Oil & Gas Operator | Oct 2025 |
| 724 | Case Oil & Gas I | | Oil & Gas Operator | Apr 1992 |
| 725 | Case Resources, LLC | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 726 | Case Sales Company Inc | Tonkawa, OK 74653-0040 | Oil & Gas Operator | Jul 2025 |
| 727 | Case'S Used Equipment | | Oil & Gas Operator | Jul 2025 |
| 728 | Case, C. W. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 729 | Casebeer, Inc. | McPherson, KS 67460 | Oil Operator | Jun 2025 |
| 730 | Casella Charles J | Avonmore, PA 15618-1028 | Oil & Gas Operator | Dec 2015 |
| 731 | Casex Company | | Oil & Gas Operator | Dec 2007 |
| 732 | Casey Musgrove Oil Company Inc | Ponca City, OK 74602 | Oil & Gas Operator | Jun 2025 |
| 733 | Casey, Carl D | | Oil Operator | Sep 2024 |
| 734 | Casey, W. J. | Fairfield, TX 75840 | Oil & Gas Operator | Oct 2025 |
| 735 | Cash Flow Oil | | Oil Operator | Jul 2003 |
| 736 | Cashco Energy Corporation | | Oil & Gas Operator | Feb 1982 |
| 737 | Cashco Oil Company | Houston, TX 77024 | Oil & Gas Operator | Aug 2003 |
| 738 | Cashco, L.L.C. | Houston, TX 77024 | Oil & Gas Operator | Jul 1999 |
| 739 | Cashion, Lyle, Company | Brandon, MS 39047 | Oil & Gas Operator | May 2008 |
| 740 | Casias Oil Well Service, Inc. | San Antonio, TX 78232 | Oil & Gas Operator | Jul 2020 |
| 741 | Casillas Operating LLC | Tulsa, OK 74103-4060 | Oil & Gas Operator | Jun 2025 |
| 742 | Casillas Petroleum Corp | Satanta, KS 67870 | Oil & Gas Operator | Jul 2025 |
| 743 | Casino Petroleum | | Oil Operator | Dec 1996 |
| 744 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 745 | Cason William J | Santee, CA 92071-2765 | Oil Operator | Sep 2019 |
| 746 | Caspen Oil, Inc. | Denver, CO 80226 | Oil & Gas Operator | Jul 1993 |
| 747 | Caspen Operating Company | Somerset, TX 78069 | Oil & Gas Operator | Mar 2008 |
| 748 | Casper Oil & Gas | Bandera, TX 78003 | Oil & Gas Operator | Oct 2002 |
| 749 | Cass Energy Corp | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 750 | Cass Energy LLC | MT Vernon, TX 75457 | Oil Operator | Oct 2025 |
| 751 | Cassadaga Valley Central School | Sinclairville, NY 14782 | Gas Operator | Dec 2024 |
| 752 | Casselman Charles Jack | Okmulgee, OK 74447-4265 | Oil & Gas Operator | Apr 2020 |
| 753 | Casselman Leases LLC | Morris, OK 74445-2509 | Oil & Gas Operator | Jun 2025 |
| 754 | Casselman Ronald H | Morris, OK 74445 | Oil & Gas Operator | Jun 2025 |
| 755 | Casselman-Sheely | Emporia, KS 66801 | Oil & Gas Operator | Oct 2021 |
| 756 | Cassidy Jr John | Stroud, OK 74079-0200 | Oil & Gas Operator | Nov 2014 |
| 757 | Cassity Company | Wichita Falls, TX 76309 | Oil & Gas Operator | Jul 2013 |
| 758 | Cassius Congdon Legacy, LLC | West Clarksville, NY 14786 | Oil & Gas Operator | Dec 2024 |
| 759 | Casteel, Hoyt F. | Graham, TX 76450 | Oil & Gas Operator | Nov 2001 |
| 760 | Castella Inc | Bartlesville, OK 74003-3712 | Oil & Gas Operator | Jun 2025 |
| 761 | Castelli Exploration, Inc. | Oklahoma City, OK 73162 | Oil & Gas Operator | Jun 2025 |
| 762 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 763 | Castillo Oil Company LLC | Luling, TX 78648 | Oil & Gas Operator | Oct 2025 |
| 764 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 765 | Castle Gas Company Inc | Pittsburgh, PA 15236-2466 | Oil & Gas Operator | Dec 2007 |
| 766 | Castle Gas Corporation | San Angelo, TX 76902 | Oil & Gas Operator | Oct 2014 |
| 767 | Castle Minerals | | Oil & Gas Operator | Dec 2018 |
| 768 | Castle Operating LLC | Oklahoma City, OK 73114-7444 | Oil & Gas Operator | Jun 2025 |
| 769 | Castle Production Company | Henderson, TX 75652 | Oil & Gas Operator | May 1997 |
| 770 | Castle Resources | | Oil Operator | Jul 2002 |
| 771 | Castle Resources, Inc. | Russell, KS 67665 | Oil & Gas Operator | Jun 2025 |
| 772 | Castle Rock Oil LLC | | Oil Operator | Aug 2025 |
| 773 | Castle-Rock Prod | | Oil Operator | Mar 1992 |
| 774 | Castlerock Ef Operating LLC | San Antonio, TX 78232 | Oil & Gas Operator | Oct 2025 |
| 775 | Castlerock Oil Company, Inc. | Addison, TX 75001 | Oil & Gas Operator | Feb 2006 |
| 776 | Castlerock Operating, LLC | San Antonio, TX 78232 | Oil & Gas Operator | Dec 2020 |
| 777 | Castlerock Resources Inc | Oklahoma City, OK 73116-3710 | Oil & Gas Operator | Jul 2020 |
| 778 | Castor Exploration, Inc. | | Oil & Gas Operator | Dec 1991 |
| 779 | Castor Production, L.L.C. | | Oil Operator | Dec 2024 |
| 780 | Caswell Bros. Oil Co. | Bowie, TX 76230 | Oil & Gas Operator | Oct 2025 |
| 781 | Cat Canyon Resources LLC | | Oil & Gas Operator | Jul 2025 |
| 782 | Cat Creek Holdings LLC | Winnett, MT 59087 | Oil Operator | Jul 2025 |
| 783 | Cat Energy, LLC | Galva, KS 67443 | Oil Operator | Aug 2008 |
| 784 | Cat Oil | Byron, WY 82412 | Oil Operator | May 2001 |
| 785 | Cat-Oil Inc. | | Oil Operator | Nov 2015 |
| 786 | Catalyst Energy Inc | Pittsburgh, PA 15218 | Oil & Gas Operator | Jul 2025 |
| 787 | Catamount Energy Partners LLC | Denver, CO 80202 | Gas Operator | Aug 2025 |
| 788 | Catamount Resources, Inc. | Grafton, WV 26354-0000 | Gas Operator | Dec 2009 |
| 789 | Catarina Petroleum L. C. | Dallas, TX 75228 | Oil & Gas Operator | Jun 2008 |
| 790 | Catena Resources Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2022 |
| 791 | Cates Betty J | Tulsa, OK 74112 | Oil & Gas Operator | Nov 2016 |
| 792 | Catfish Minerals LLC | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 793 | Catfish Oil | | Oil Operator | May 2025 |
| 794 | Cather Rogers Barnes & Cree | | Oil & Gas Operator | Dec 2009 |
| 795 | Cather, Barnes & Cree | | Oil & Gas Operator | Dec 2009 |
| 796 | Cather-Herley Oil Company | | Oil & Gas Operator | Aug 2025 |
| 797 | Cathexis Oil & Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2014 |
| 798 | Cathey Oil, Inc. | | Oil & Gas Operator | Aug 2009 |
| 799 | Cathey Petroleum Company, Inc. | Big Spring, TX 79720 | Oil & Gas Operator | Apr 2008 |
| 800 | Cathey Production Company | Ryan, OK 73565-0485 | Oil Operator | Dec 2010 |