| 5601 | Circle 9 Resources LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Jul 2026 |
| 5602 | Circle B Oil & Gas | Bowie, TX 76230 | Oil & Gas Operator | Dec 2021 |
| 5603 | Circle C Oilfield Supply Inc | Wetumka, OK 74883-0068 | Oil & Gas Operator | Apr 2017 |
| 5604 | Circle C Operations | Winnsboro, TX 75494 | Oil Operator | Sep 2026 |
| 5605 | Circle D Oil & Gas, Inc. | Brownwood, TX 76801 | Oil & Gas Operator | Sep 2026 |
| 5606 | Circle E Oil - E | | Oil Operator | May 1990 |
| 5607 | Circle H Oil Company | Big Spring, TX 79721 | Oil & Gas Operator | Apr 2020 |
| 5608 | Circle K Enterprises | | Oil & Gas Operator | Aug 2023 |
| 5609 | Circle K Oil & Gas Inc | Sand Springs, OK 74063 | Oil & Gas Operator | Jun 2026 |
| 5610 | Circle Ridge Production, Inc. | Graham, TX 76450 | Oil & Gas Operator | Sep 2026 |
| 5611 | Circle T Oil | | Oil Operator | Nov 2024 |
| 5612 | Circle W Oil & Gas Company | Pampa, TX 79066 | Oil & Gas Operator | Sep 2026 |
| 5613 | Circle-S Energy, LLC | McKinney, TX 75071 | Oil & Gas Operator | Sep 2026 |
| 5614 | Circleville Gas Co | Westerville, OH 43081 | Oil & Gas Operator | Dec 2004 |
| 5615 | Ciri Production Company | | Gas Operator | Mar 1994 |
| 5616 | Ciris Energy Inc | Centennial, CO 80112 | Gas Operator | Dec 2016 |
| 5617 | Cirque Resources LP | Denver, CO 80202 | Oil & Gas Operator | Aug 2016 |
| 5618 | Cirrus Exploration Company | Prosper, TX 75078 | Oil & Gas Operator | Sep 2026 |
| 5619 | Cirrus Production Company | Enid, OK 73702 | Oil & Gas Operator | Jun 2026 |
| 5620 | Cisco Operating LLC | Plano, TX 75024 | Oil & Gas Operator | Jul 2026 |
| 5621 | Cisco Petroleum, Inc. | | Oil & Gas Operator | Oct 2010 |
| 5622 | Cisco Production Company, LLC | Victoria, TX 77902 | Oil & Gas Operator | May 2012 |
| 5623 | Citadel Exploration Inc. | | Oil Operator | Dec 2025 |
| 5624 | Citadel Oil LLC | Edmond, OK 73083 | Oil Operator | May 2026 |
| 5625 | Citadel Prod Company Inc | Denver, CO 80201 | Oil Operator | Sep 1996 |
| 5626 | Citation Energy | | Oil & Gas Operator | Jul 1993 |
| 5627 | Citation Energy Company | Marietta, OH 45750 | Oil & Gas Operator | Dec 2025 |
| 5628 | Citation Oil & G | | Oil & Gas Operator | Dec 1996 |
| 5629 | Citation Oil & Gas Corp | Houston, TX 77269 | Oil & Gas Operator | Sep 2026 |
| 5630 | Cities Serv Oil & Gas Corp | Oklahoma City, OK 73112 | Oil & Gas Operator | Sep 1964 |
| 5631 | Cities Service Company | | Oil & Gas Operator | Mar 1983 |
| 5632 | Cities Service Oil & Gas Corp | | Oil & Gas Operator | Mar 1988 |
| 5633 | Cities Service Oil Co. | Houston, TX 77227 | Oil & Gas Operator | Dec 1986 |
| 5634 | Cities Services Company | | Oil & Gas Operator | Mar 2008 |
| 5635 | Citizen Energy II LLC | Tulsa, OK 74103-3729 | Oil & Gas Operator | Apr 2025 |
| 5636 | Citizen Energy III LLC | Devner, CO 80202 | Oil & Gas Operator | Jun 2026 |
| 5637 | Citizen Energy Ventures LLC | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2026 |
| 5638 | Citmoco Services, Inc. | | Oil Operator | Jan 1971 |
| 5639 | Citori Oil Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Nov 2004 |
| 5640 | Citori Oil Company, LLC | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2014 |
| 5641 | Citronelle Operating Co., LLC | | Oil & Gas Operator | Sep 1997 |
| 5642 | Citrus Energy Corporation | Castle Rock, CO 80104 | Oil & Gas Operator | Dec 2025 |
| 5643 | Cits BK & Trust Of Springhill | | Oil & Gas Operator | Jun 1990 |
| 5644 | City & County Of Denver | | Oil & Gas Operator | Sep 2023 |
| 5645 | City Of Akron | Akron, OH 44308 | Oil & Gas Operator | Dec 2025 |
| 5646 | City Of Baker | Baker, MT 59313 | Oil & Gas Operator | Jun 2026 |
| 5647 | City Of Brady | Brady, TX 76825 | Gas Operator | Feb 1998 |
| 5648 | City Of Chanute | Chanute, KS 66720 | Oil Operator | Feb 1994 |
| 5649 | City Of Dumas | Dumas, TX 79029 | Gas Operator | Sep 2026 |
| 5650 | City Of Garden City, Kansas | Garden City, KS 67846 | Gas Operator | May 2026 |
| 5651 | City Of Hermosa Beach | | Oil & Gas Operator | Dec 2005 |
| 5652 | City Of Hugoton, Kansas | Hugoton, KS 67951 | Gas Operator | May 2026 |
| 5653 | City Of Huntington Beach (Fire Dept.) | | Oil & Gas Operator | Dec 2025 |
| 5654 | City Of McLean | McLean, TX 79057 | Gas Operator | Aug 2025 |
| 5655 | City Of Newport Beach | | Oil & Gas Operator | Jul 2026 |
| 5656 | City Of Santa Fe Springs | | Oil Operator | Dec 2007 |
| 5657 | City Of Satanta | Satanta, KS 67870 | Gas Operator | May 2026 |
| 5658 | City Of Sunray Utilities | Sunray, TX 79086 | Oil & Gas Operator | Sep 2026 |
| 5659 | City Of White Deer | White Deer, TX 79097 | Gas Operator | May 2017 |
| 5660 | City Oil Corp. Oper. For | | Oil & Gas Operator | Dec 1989 |
| 5661 | Civego, Inc. | | Oil & Gas Operator | Jul 1994 |
| 5662 | Civic Energy Corporation | Colony, OK 73021 | Oil & Gas Operator | Jul 2026 |
| 5663 | Civiletto, George & Wendy | Fredonia, NY 14063 | Gas Operator | Dec 2025 |
| 5664 | Civitas North LLC | | Oil & Gas Operator | May 2026 |
| 5665 | Civitas Permian Operating, LLC | Midland, TX 79707 | Oil & Gas Operator | Sep 2026 |
| 5666 | Civron Petroleum Res., LLC | San Antonio, TX 78229 | Oil & Gas Operator | Sep 2026 |
| 5667 | CJ Oil Inc | Madison, KS 66860 | Oil Operator | May 2026 |
| 5668 | CJR Operating LLC | Wister, OK 74966 | Gas Operator | Jun 2026 |
| 5669 | CJRW Oil & Gas | MC Camey, TX 79752 | Oil Operator | Sep 2026 |
| 5670 | CJT Oil Company LLC | Decatur, TX 76234 | Oil Operator | Sep 2026 |
| 5671 | CK Oil | | Oil Operator | Mar 2026 |
| 5672 | CK Oil & Gas LLC | Herington, KS 67449 | Oil & Gas Operator | Dec 2023 |
| 5673 | CK Operating Company, LLC | Wichita Falls, TX 76308 | Oil Operator | Dec 2025 |
| 5674 | CK Resources | Cleveland, OK 74020-0772 | Oil Operator | Aug 2013 |
| 5675 | CKB Corporation | Borger, TX 79008 | Oil & Gas Operator | Aug 1997 |
| 5676 | CKT Energy LLC | Dallas, TX 75379 | Oil & Gas Operator | Sep 2020 |
| 5677 | CL&F Operating LLC | Spring, TX 77389 | Oil & Gas Operator | Dec 2022 |
| 5678 | Cla-Mar Oil Company, LLC | Hays, KS 67601 | Oil Operator | Dec 2019 |
| 5679 | Claassen Oil And Gas Inc | Estes Park, CO 80517 | Oil & Gas Operator | May 2026 |
| 5680 | Claborn Julia | Okmulgee, OK 74447-9781 | Oil & Gas Operator | Mar 2022 |
| 5681 | Claco Oil Co | Artesia, NM 88210 | Oil & Gas Operator | Dec 2014 |
| 5682 | Claiborne-McDonald Inc | Chickasha, OK 73018 | Oil Operator | Jul 2007 |
| 5683 | Claibourn, Darrel R. | Neodesha, KS 66757 | Oil Operator | Oct 2011 |
| 5684 | Clair Oil, Inc. | Russell, KS 67665 | Oil Operator | Nov 2019 |
| 5685 | Clamp Operating | San Antonio, TX 78264 | Oil & Gas Operator | Apr 2002 |
| 5686 | Clamp Operating Incorporated | San Antonio, TX 78264 | Oil & Gas Operator | Mar 2011 |
| 5687 | Clapp Carl O | Cedar Vale, KS 67024 | Oil Operator | Aug 2013 |
| 5688 | Clapp Oil LLC | | Oil Operator | May 2026 |
| 5689 | Clarco Gas Co., Inc. | Westmont, IL 60559 | Oil Operator | Dec 2011 |
| 5690 | Claremont Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Apr 2026 |
| 5691 | Claremont Energy | | Gas Operator | Dec 1993 |
| 5692 | Claremont Exploration Inc | Tulsa, OK 74103-4107 | Oil & Gas Operator | Jun 1997 |
| 5693 | Clarence F. Routon, Jr. | | Oil Operator | Apr 1990 |
| 5694 | Clarence K Tussel Jr LTD | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2025 |
| 5695 | Clarence R. Barnett Inc. | | Oil & Gas Operator | Jul 2025 |
| 5696 | Clarita Operating LLC | Ada, OK 74821 | Oil Operator | Jun 2022 |
| 5697 | Clark And Clark | Princeton, NJ 08540-1930 | Oil & Gas Operator | Jul 2013 |
| 5698 | Clark B & Cahoj | | Oil Operator | Apr 1995 |
| 5699 | Clark Blake | | Gas Operator | Sep 2023 |
| 5700 | Clark Energy, LLC | Chanute, KS 66720 | Oil & Gas Operator | Jun 2022 |