| 5901 | CK5 Services LLC | Zephyr, TX 76890 | Oil & Gas Operator | Sep 2025 |
| 5902 | CKB Corporation | Borger, TX 79008 | Oil & Gas Operator | Aug 1997 |
| 5903 | CKT Energy LLC | Dallas, TX 75379 | Oil & Gas Operator | Sep 2020 |
| 5904 | CL&F Operating LLC | Spring, TX 77389 | Oil & Gas Operator | Dec 2022 |
| 5905 | Cla-Mar Oil Company, LLC | Hays, KS 67601 | Oil Operator | Dec 2019 |
| 5906 | Claassen Oil And Gas Inc | Estes Park, CO 80517 | Oil & Gas Operator | Sep 2025 |
| 5907 | Claborn Julia | Okmulgee, OK 74447-9781 | Oil & Gas Operator | Mar 2022 |
| 5908 | Claco Oil Co | Artesia, NM 88210 | Oil & Gas Operator | Dec 2014 |
| 5909 | Claiborne-McDonald Inc | Chickasha, OK 73018 | Oil Operator | Jul 2007 |
| 5910 | Claibourn, Darrel R. | Neodesha, KS 66757 | Oil Operator | Oct 2011 |
| 5911 | Clair Oil, Inc. | Russell, KS 67665 | Oil Operator | Nov 2019 |
| 5912 | Clamp Operating | San Antonio, TX 78264 | Oil & Gas Operator | Apr 2002 |
| 5913 | Clamp Operating Incorporated | San Antonio, TX 78264 | Oil & Gas Operator | Mar 2011 |
| 5914 | Clapp Carl O | Cedar Vale, KS 67024 | Oil Operator | Aug 2013 |
| 5915 | Clapp Oil LLC | | Oil Operator | Sep 2025 |
| 5916 | Clarco Gas Co., Inc. | Westmont, IL 60559 | Oil Operator | Dec 2011 |
| 5917 | Claremont Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Feb 2017 |
| 5918 | Claremont Energy | | Gas Operator | Dec 1993 |
| 5919 | Claremont Exploration Inc | Tulsa, OK 74103-4107 | Oil & Gas Operator | Jun 1997 |
| 5920 | Clarence F. Routon, Jr. | | Oil Operator | Apr 1990 |
| 5921 | Clarence K Tussel Jr LTD | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2024 |
| 5922 | Clarence R. Barnett Inc. | | Oil & Gas Operator | Jul 2025 |
| 5923 | Clarita Operating LLC | Ada, OK 74821 | Oil Operator | Jun 2022 |
| 5924 | Clark And Clark | Princeton, NJ 08540-1930 | Oil & Gas Operator | Jul 2013 |
| 5925 | Clark B & Cahoj | | Oil Operator | Apr 1995 |
| 5926 | Clark Blake | | Gas Operator | Sep 2023 |
| 5927 | Clark Energy, LLC | Chanute, KS 66720 | Oil & Gas Operator | Jun 2022 |
| 5928 | Clark Exploratio | | Oil & Gas Operator | Jun 1991 |
| 5929 | Clark Exploration Company | Highlands Ranch, CO 80126-7645 | Oil & Gas Operator | Nov 2024 |
| 5930 | Clark Krista | Ada, OK 74820-8595 | Oil Operator | Sep 2001 |
| 5931 | Clark Oil & Gas Inc | | Oil & Gas Operator | Dec 1990 |
| 5932 | Clark Oil Co. | Dallas, TX 75360 | Oil & Gas Operator | Feb 2026 |
| 5933 | Clark Oil Producing Company | | Oil & Gas Operator | Oct 1979 |
| 5934 | Clark Oil, LLC | Wellsville, KS 66092 | Oil Operator | Apr 2022 |
| 5935 | Clark Operating | Wichita Falls, TX 76308 | Oil & Gas Operator | Aug 2003 |
| 5936 | Clark Operating Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 5937 | Clark Operating Services Inc | Okmulgee, OK 74447 | Oil & Gas Operator | May 2013 |
| 5938 | Clark Well Service | Depew, OK 74028-0296 | Oil & Gas Operator | Aug 2013 |
| 5939 | Clark, B. C. | Cross Plains, TX 76443 | Oil Operator | Dec 2007 |
| 5940 | Clark, Daniel J. | Auburn, NY 13021 | Gas Operator | Dec 2024 |
| 5941 | Clark, Daryl | Phillipsburg, KS 67661 | Oil Operator | Aug 2025 |
| 5942 | Clark, Donald E. | | Gas Operator | Dec 2003 |
| 5943 | Clark, Donald-Roger Young | | Oil & Gas Operator | Jan 1988 |
| 5944 | Clark, G. A., Trustee | San Antonio, TX 78210 | Oil & Gas Operator | Nov 2017 |
| 5945 | Clark, John M. | Midland, TX 79701 | Oil & Gas Operator | Dec 1993 |
| 5946 | Clark, John M., Inc. | Midland, TX 79704 | Oil & Gas Operator | Feb 2026 |
| 5947 | Clark, N.G. Dba Glenn, Inc | | Oil & Gas Operator | Dec 2021 |
| 5948 | Clark, Noel D. Et Al | | Oil & Gas Operator | Mar 1994 |
| 5949 | Clark, Richard E., Inc. | Longview, TX 75604 | Oil & Gas Operator | May 2001 |
| 5950 | Clark, Robert A. | Wichita, KS 67202 | Gas Operator | Jul 1990 |
| 5951 | Clarkco Services, Inc. | | Oil & Gas Operator | Oct 2025 |
| 5952 | Clarke Corporati | Medicine Lodge, KS 67104 | Oil & Gas Operator | Sep 2025 |
| 5953 | Clarkston Oil Co | | Oil Operator | Dec 2024 |
| 5954 | Clarkston Oil Corp | | Oil Operator | Dec 2024 |
| 5955 | Claron Corporation | Houston, TX 77219 | Oil & Gas Operator | Feb 2026 |
| 5956 | Class Oil | Hays, KS 67601 | Oil Operator | Jun 1991 |
| 5957 | Class Petroleum Corporation | Barnsdall, OK 74002 | Oil Operator | Aug 2013 |
| 5958 | Classic Energy Incorporated | Tyler, TX 75701 | Oil & Gas Operator | Jul 2005 |
| 5959 | Classic Hydrocarbons, Inc. | | Gas Operator | Dec 2007 |
| 5960 | Classic Oil & Gas Resources Inc | | Gas Operator | Dec 2008 |
| 5961 | Classic Oil & Gas, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Jan 2004 |
| 5962 | Classic Operating Co. LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 5963 | Classic Petroleum Partners, Inc. | Whitehouse, TX 75791 | Oil & Gas Operator | Feb 2026 |
| 5964 | Classic Well Service, Inc. | Claflin, KS 67525 | Oil Operator | Dec 2019 |
| 5965 | Claude Debeaux, Jr. Et Al | | Oil Operator | Dec 1999 |
| 5966 | Claude S. Hinds | | Oil Operator | Aug 1985 |
| 5967 | Claude-Maggie Co. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 5968 | Clausen, A. G. | Cross Plains, TX 76443 | Oil & Gas Operator | Feb 2026 |
| 5969 | Clausing, Garry | Coffeyville, KS 67337 | Oil Operator | Apr 2024 |
| 5970 | Claussen Roy A & | | Oil Operator | Jun 1986 |
| 5971 | Clavo Oil, LLC | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 5972 | Clawson, Merle Eugene | McCune, KS 66753 | Oil Operator | Nov 2016 |
| 5973 | Clay A Muegge | | Oil & Gas Operator | Nov 2025 |
| 5974 | Clay Exploration, Inc. | Spring, TX 77387 | Oil & Gas Operator | Jun 2019 |
| 5975 | Clay Investments LLC | Stillwater, OK 74075-3600 | Oil & Gas Operator | Jan 2021 |
| 5976 | Clay Oil & Gas Co | Zanesville, OH 43701 | Oil Operator | Dec 1991 |
| 5977 | Clay Petroleum | Prosper, TX 75078 | Oil & Gas Operator | Feb 2023 |
| 5978 | Clay, Charles E. | Jacksboro, TX 76458 | Oil & Gas Operator | Sep 2010 |
| 5979 | Clay, Jerry H. | Tyler, TX 75702 | Oil & Gas Operator | Mar 2006 |
| 5980 | Claybanks Oil Co LLC | | Oil Operator | Jun 2019 |
| 5981 | Claybrook Drilling Co Inc | | Oil & Gas Operator | Sep 2014 |
| 5982 | Claybrook Production Co. Inc. | Wewoka, OK 74884-1380 | Oil & Gas Operator | Jun 2014 |
| 5983 | Clayton Corp Petro & Natural Gas Prod | Lakewood, CO 80228-1836 | Oil & Gas Operator | Oct 2020 |
| 5984 | Clayton Corp Petro & NTRL Gas Prodn | Lakewood, CO 80228 | Oil & Gas Operator | Dec 2009 |
| 5985 | Clayton Corporat | | Oil & Gas Operator | Jun 1994 |
| 5986 | Clayton Corporation | Golden, CO 80401 | Oil & Gas Operator | Dec 2019 |
| 5987 | Clayton Investment | Farmington, NM 87401 | Oil & Gas Operator | Jun 1995 |
| 5988 | Clayton Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | May 2004 |
| 5989 | Clayton W. Williams, Jr. | | Oil & Gas Operator | Sep 1986 |
| 5990 | Clayton W. Williams, Jr., Inc. | | Oil & Gas Operator | May 1993 |
| 5991 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 5992 | CLC Operations Inc | Midland, TX 79701 | Oil & Gas Operator | Mar 1997 |
| 5993 | Clean Energy Exploration & Production LLC | Norristown, PA 19403 | Gas Operator | Nov 2025 |
| 5994 | Clean Energy Systems Placerita Inc. | | Oil & Gas Operator | Oct 2025 |
| 5995 | Clean Gas, Inc | Hindman, KY 41822 | Oil & Gas Operator | Dec 2023 |
| 5996 | Clean Oil LLC | Ada, OK 74820 | Oil & Gas Operator | Oct 2025 |
| 5997 | Cleantex Oilfield Services, LLC | Tyler, TX 75702 | Oil Operator | Feb 2026 |
| 5998 | Clear Brooke Ranches, LLC | Fort Worth, TX 76179 | Oil & Gas Operator | Feb 2026 |
| 5999 | Clear Creek Energy LLC | | Oil & Gas Operator | Dec 2021 |
| 6000 | Clear Creek Exploration LLC | Fredonia, KS 66736 | Gas Operator | Apr 2011 |