| 701 | Calpine Natural Gas Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2002 |
| 702 | Calpine Natural Gas Company L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 703 | Calpine Natural Gas L.P. | Houston, TX 77002 | Oil & Gas Operator | Dec 2005 |
| 704 | Calto Operating Company, Inc. | Dallas, TX 75225 | Oil & Gas Operator | May 2004 |
| 705 | Calumet Lubricants Company | | Oil Operator | Dec 1993 |
| 706 | Calumet Refining Co. | | Oil Operator | May 1991 |
| 707 | Calyx Exploration & Production | | Oil & Gas Operator | Jul 1991 |
| 708 | Camar Exploration | | Oil Operator | Jan 1989 |
| 709 | Cambridge Energy Corporation | | Oil & Gas Operator | Jul 2003 |
| 710 | Camco Resources, Inc. | | Oil Operator | Aug 1991 |
| 711 | Cameron Development Co., Inc. | | Oil & Gas Operator | Mar 1988 |
| 712 | Cameron LNG, LLC | | Oil Operator | Jan 2025 |
| 713 | Camex Operating Company | | Oil & Gas Operator | Dec 2024 |
| 714 | Camex, Inc. | | Oil & Gas Operator | Jun 1992 |
| 715 | Campbell & Assoc.-Ring | | Oil Operator | Nov 1980 |
| 716 | Campbell & Associates | | Oil & Gas Operator | Aug 1987 |
| 717 | Campbell Energy Corporation | | Oil & Gas Operator | May 1992 |
| 718 | Campbell Wells Corporation | | Oil Operator | Dec 1995 |
| 719 | Campground Corporation | | Oil Operator | Nov 2023 |
| 720 | Camterra Resources, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Dec 2025 |
| 721 | Can Do Enterprises | | Oil Operator | Dec 2024 |
| 722 | Canada Crown Inv Corporation | | Oil & Gas Operator | Apr 1998 |
| 723 | Candice Venture #1 | | Oil & Gas Operator | May 1992 |
| 724 | Candleridge Oil, Inc. | Fort Worth, TX 76109 | Oil & Gas Operator | Jun 2003 |
| 725 | Cankton Oil Company | | Oil Operator | May 1985 |
| 726 | Canlan Oil Company | | Oil & Gas Operator | Mar 1992 |
| 727 | Cannon Operating Company LLC | Garland, TX 75043 | Oil Operator | Dec 2025 |
| 728 | Canstar Oil & Gas, Inc. | | Oil & Gas Operator | Dec 1994 |
| 729 | Cantium, LLC | | Oil & Gas Operator | Dec 2024 |
| 730 | Cap Production | | Oil Operator | Dec 2024 |
| 731 | Capital Gas, Inc. | | Gas Operator | Jan 1998 |
| 732 | Capturepoint LLC | Allen, TX 75013 | Oil & Gas Operator | Dec 2025 |
| 733 | Car-Tex Producing Company | | Oil & Gas Operator | Dec 1994 |
| 734 | Carder Oil Company | | Oil & Gas Operator | Dec 2024 |
| 735 | Cardinal Expl And Prod | | Oil & Gas Operator | May 2019 |
| 736 | Cardinal Oil & Gas, Inc. | | Oil & Gas Operator | Jun 1995 |
| 737 | Cardinal Operating Corporation | Waxahachie, TX 75165 | Oil & Gas Operator | Jan 1997 |
| 738 | Cardinal Petroleum Corp Of La | | Oil Operator | May 2003 |
| 739 | Cardneaux Inc | | Oil & Gas Operator | Aug 2009 |
| 740 | Cargas Operating Company | | Oil & Gas Operator | Dec 2024 |
| 741 | Caribbean Oil & Gas Corp | | Oil & Gas Operator | Mar 1980 |
| 742 | Caribe Resources, Inc. | | Oil & Gas Operator | Jan 1985 |
| 743 | Carl E. Hansford | | Oil Operator | Oct 1980 |
| 744 | Carl Oil & Gas Co. | Bakersfield, CA 93309 | Oil & Gas Operator | Dec 1995 |
| 745 | Carl Oil & Gas Co.-CNG | | Oil & Gas Operator | Dec 1995 |
| 746 | Carl P. Roppolo, Jr. | | Oil & Gas Operator | Mar 1991 |
| 747 | Carl W Jones Et Al | | Oil & Gas Operator | Jul 1995 |
| 748 | Carlson Petroleum Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 749 | Carmet Oil, Inc. | | Oil & Gas Operator | Dec 1990 |
| 750 | Caroline Hunt Schoellkopf | | Oil & Gas Operator | Aug 1987 |
| 751 | Caroline Hunt Trust Estate | | Oil & Gas Operator | Mar 1987 |
| 752 | Carr Petroleum, Inc. | | Oil Operator | Apr 1987 |
| 753 | Carraway Co. | | Oil Operator | Apr 2006 |
| 754 | Carrizo Oil & Gas, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 755 | Carrollton Resources Corp. | | Oil & Gas Operator | Sep 2000 |
| 756 | Carter & Rorex | | Oil Operator | Dec 1991 |
| 757 | Carter Resources | Kilgore, TX 75663 | Oil & Gas Operator | Jan 2005 |
| 758 | Carter-Langham, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Dec 2025 |
| 759 | Caruthers Operating Co., Inc. | | Oil & Gas Operator | Jul 2010 |
| 760 | Caruthers Producing Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2019 |
| 761 | Cashco Energy Corporation | | Oil & Gas Operator | Feb 1982 |
| 762 | Cashco Oil Company | Houston, TX 77024 | Oil & Gas Operator | Aug 2003 |
| 763 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Dec 2025 |
| 764 | Caspen Oil, Inc. | Denver, CO 80226 | Oil & Gas Operator | Jul 1993 |
| 765 | Caspen Operating Company | Somerset, TX 78069 | Oil & Gas Operator | Mar 2008 |
| 766 | Castex Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 767 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 768 | Castlerock Oil Company, Inc. | Addison, TX 75001 | Oil & Gas Operator | Feb 2006 |
| 769 | Castor Exploration, Inc. | | Oil & Gas Operator | Dec 1991 |
| 770 | Castor Production, L.L.C. | | Oil Operator | Dec 2024 |
| 771 | Cat-Oil Inc. | | Oil Operator | Nov 2015 |
| 772 | Cathexis Oil & Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2014 |
| 773 | Cathey Oil, Inc. | | Oil & Gas Operator | Aug 2009 |
| 774 | Catlett & Ferguson-Carl O & G | | Oil & Gas Operator | Jun 1978 |
| 775 | Cavalcade Operating Company LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2017 |
| 776 | Cavalry Resources LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2010 |
| 777 | Cavenham Energy Resources Inc. | | Oil & Gas Operator | Apr 1991 |
| 778 | Cavenham Energy Resrces Inc JV | | Oil Operator | Mar 1991 |
| 779 | Cavenham Forest Ind., Inc. | | Oil & Gas Operator | Nov 1987 |
| 780 | Cavenham Forest Ind., Inc. J V | | Oil Operator | Nov 1987 |
| 781 | Cayman Exploration Corp | Tulsa, OK 74119-1323 | Oil & Gas Operator | Jun 2001 |
| 782 | Cayman Resources Corporation | Tulsa, OK 74119-1323 | Oil & Gas Operator | Jun 2001 |
| 783 | Caza Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 784 | CB Oil Company | Drumright, OK 74030 | Oil & Gas Operator | Jul 2025 |
| 785 | Cecil Brand | | Oil & Gas Operator | Mar 2002 |
| 786 | Cedar Creek Consulting Inc | | Oil Operator | Jan 2025 |
| 787 | Cedyco Corporation | Houston, TX 77227 | Oil & Gas Operator | Nov 2008 |
| 788 | Cei Production Company | Dallas, TX 75225 | Oil & Gas Operator | Sep 1998 |
| 789 | Ceka Gas, Div Of GTC | | Oil & Gas Operator | May 1988 |
| 790 | Cel Properties LLC | | Oil & Gas Operator | Jan 2025 |
| 791 | Celeron Oil & Gas Company | | Oil & Gas Operator | Dec 1987 |
| 792 | Celt Oil, Inc. | | Oil & Gas Operator | Jun 1986 |
| 793 | Cenco, Inc. | | Oil & Gas Operator | Mar 2022 |
| 794 | Cenergy Exploration Company | Dallas, TX 75231 | Oil & Gas Operator | Sep 2000 |
| 795 | Cenla Oil Company, LLC | | Oil Operator | Dec 2024 |
| 796 | Centennial Exploration, Inc. | | Oil & Gas Operator | Dec 1985 |
| 797 | Centergate Resources LLC | | Oil & Gas Operator | Dec 2024 |
| 798 | Centerpoint Energy FLD Ser Inc | | Oil Operator | Feb 2011 |
| 799 | Central Crude, Inc. | | Oil & Gas Operator | Jul 2014 |
| 800 | Central Min Oper Co, Inc. | | Gas Operator | Mar 1994 |