| 5901 | Claybanks Oil Co LLC | | Oil Operator | Jun 2019 |
| 5902 | Claybrook Drilling Co Inc | | Oil & Gas Operator | Sep 2014 |
| 5903 | Claybrook Production Co. Inc. | Wewoka, OK 74884-1380 | Oil & Gas Operator | Jun 2014 |
| 5904 | Clayton Corp Petro & Natural Gas Prod | Lakewood, CO 80228-1836 | Oil & Gas Operator | Oct 2020 |
| 5905 | Clayton Corp Petro & NTRL Gas Prodn | Lakewood, CO 80228 | Oil & Gas Operator | Dec 2009 |
| 5906 | Clayton Corporat | | Oil & Gas Operator | Jun 1994 |
| 5907 | Clayton Corporation | Golden, CO 80401 | Oil & Gas Operator | Dec 2019 |
| 5908 | Clayton Investment | Farmington, NM 87401 | Oil & Gas Operator | Jun 1995 |
| 5909 | Clayton Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | May 2004 |
| 5910 | Clayton W. Williams, Jr. | | Oil & Gas Operator | Sep 1986 |
| 5911 | Clayton W. Williams, Jr., Inc. | | Oil & Gas Operator | May 1993 |
| 5912 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 5913 | CLC Operations Inc | Midland, TX 79701 | Oil & Gas Operator | Mar 1997 |
| 5914 | Clean Energy Exploration & Production LLC | Norristown, PA 19403 | Gas Operator | Dec 2025 |
| 5915 | Clean Energy Systems Placerita Inc. | | Oil & Gas Operator | Dec 2025 |
| 5916 | Clean Gas, Inc | Hindman, KY 41822 | Oil & Gas Operator | Dec 2023 |
| 5917 | Clean Oil LLC | Ada, OK 74820 | Oil & Gas Operator | Dec 2025 |
| 5918 | Cleantex Oilfield Services, LLC | Tyler, TX 75702 | Oil Operator | Mar 2026 |
| 5919 | Clear Brooke Ranches, LLC | Fort Worth, TX 76179 | Oil & Gas Operator | Mar 2026 |
| 5920 | Clear Creek Energy LLC | | Oil & Gas Operator | Dec 2021 |
| 5921 | Clear Creek Exploration LLC | Fredonia, KS 66736 | Gas Operator | Apr 2011 |
| 5922 | Clear Creek Oil Co | Nova, OH 44859 | Oil & Gas Operator | Dec 2018 |
| 5923 | Clear Creek Royalty LLC | Tulsa, OK 74137 | Oil & Gas Operator | Jul 2023 |
| 5924 | Clear Fork Gas Company | Albany, TX 76430 | Oil & Gas Operator | Mar 2026 |
| 5925 | Clear Fork, Incorporated | Abilene, TX 79604 | Oil & Gas Operator | Mar 2026 |
| 5926 | Clear Lake Oil Co. | | Oil Operator | Jan 2025 |
| 5927 | Clear Water Inc. | Midland, TX 79710 | Oil & Gas Operator | Mar 2026 |
| 5928 | Clearfield Energy Resources & Management Inc. | | Oil & Gas Operator | Dec 1998 |
| 5929 | Clearfork Operating LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2011 |
| 5930 | Clearfork Petroleum Inc. (A) | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2026 |
| 5931 | Clearfork Production, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2018 |
| 5932 | Clearly Petroleum, LLC | Houston, TX 77086 | Oil & Gas Operator | Jun 2020 |
| 5933 | Cleary Exploration LLC | Oklahoma City, OK 73112-7221 | Oil & Gas Operator | Oct 2014 |
| 5934 | Cleary Jo Anne | Saint Louis, OK 74866 | Oil Operator | Oct 2025 |
| 5935 | Cleary Jon C | Lancaster, OH 43130 | Gas Operator | Dec 2022 |
| 5936 | Cleary Petroleum Corporation | Edmond, OK 73083 | Oil & Gas Operator | Jul 2019 |
| 5937 | Cleaveland Price Inc | Trafford, PA 15085-9550 | Gas Operator | Dec 2025 |
| 5938 | Cleaver Loraine | | Oil Operator | Dec 1996 |
| 5939 | Cleaver, Loraine G. (Deceased) Estate | Iola, KS 66749 | Oil Operator | Nov 2009 |
| 5940 | Cleere Operating LLC | Shawnee, OK 74804-2610 | Oil Operator | Dec 2025 |
| 5941 | Clem Energy LLC | | Oil & Gas Operator | Dec 2021 |
| 5942 | Clements Energy, Inc. | | Oil & Gas Operator | Oct 1987 |
| 5943 | Clements Exploration Co | Oklahoma City, OK 73132-5922 | Oil & Gas Operator | Jan 2006 |
| 5944 | Clements Operating Company, Inc. | Luling, TX 78648 | Oil & Gas Operator | Aug 2003 |
| 5945 | Clements-B & MCK - Luffey | | Gas Operator | Apr 1979 |
| 5946 | Clemishire Don | Hominy, OK 74035 | Oil & Gas Operator | Dec 2025 |
| 5947 | Clemishire, Brian S | | Oil & Gas Operator | Nov 2014 |
| 5948 | Clemishire, Jerry L | | Oil & Gas Operator | Dec 2025 |
| 5949 | Clemishire, Mark E | | Oil Operator | Dec 2025 |
| 5950 | Clemons, Tony W. | Minden, LA 71055 | Oil & Gas Operator | Dec 2016 |
| 5951 | Clemshire Bob | Hominy, OK 74035 | Oil & Gas Operator | Dec 2025 |
| 5952 | Clemshire Drilling Company | Tulsa, OK 74105 | Oil Operator | Dec 2025 |
| 5953 | Clendening, John A | | Oil Operator | Dec 2021 |
| 5954 | Cleo Oil, Inc. | Olney, TX 76374 | Oil & Gas Operator | May 1997 |
| 5955 | Cleveland Cameron Gas Co | Waynesburg, PA 15370-1437 | Gas Operator | Dec 2025 |
| 5956 | Cleveland Oil & Gas | Wichita Falls, TX 76308 | Oil Operator | Mar 2026 |
| 5957 | Cleveland Oil Company,L.L.C.,The | Midland, TX 79702 | Oil & Gas Operator | Sep 1999 |
| 5958 | Cleveland Production Company | Summit, MS 39666 | Oil & Gas Operator | Jul 1999 |
| 5959 | Cleveland Rod & Tracy | Elmore City, OK 73433-9467 | Oil & Gas Operator | Jul 2023 |
| 5960 | Click Betty | Stigler, OK 74462-0081 | Oil & Gas Operator | Feb 2016 |
| 5961 | Click Corp | Monroe, LA 71207 | Oil & Gas Operator | Jan 2025 |
| 5962 | Click Energy Company | Houston, TX 77269 | Oil & Gas Operator | Mar 2026 |
| 5963 | Click Robert R | Dallas, TX 75231 | Oil & Gas Operator | Nov 1995 |
| 5964 | Clide Oil Corp. | Iraan, TX 79744 | Oil & Gas Operator | Nov 2015 |
| 5965 | Clifford & Scott McKeever | Clarksburg, PA 15725 | Gas Operator | Dec 2024 |
| 5966 | Clifford C. Or Mary A. Terry | Dadeville, AL 36853 | Oil Operator | Feb 2003 |
| 5967 | Clifford Resourc | | Oil & Gas Operator | Mar 1989 |
| 5968 | Clifford Resources Inc | Oklahoma City, OK 73120 | Oil & Gas Operator | Jul 2015 |
| 5969 | Cliffs Drilling Company | | Oil & Gas Operator | Dec 1984 |
| 5970 | Cliffs Oil And Gas Company | | Oil & Gas Operator | Oct 1997 |
| 5971 | Cliffwood Production Co. | Houston, TX 77090 | Oil & Gas Operator | Aug 2013 |
| 5972 | Clift Cary E | Chickasha, OK 73018-6305 | Oil & Gas Operator | Jun 2025 |
| 5973 | Clifton & Associates Inc | Tulsa, OK 74133 | Oil & Gas Operator | May 2020 |
| 5974 | Clifton Consulting Inc | Piedmont, OK 73078-0180 | Gas Operator | Dec 2025 |
| 5975 | Clifton Oil | Muenster, TX 76252 | Oil & Gas Operator | Mar 2006 |
| 5976 | Clifton, B.W. | Graham, TX 76450 | Oil & Gas Operator | Mar 2000 |
| 5977 | Clifton, Joe B. Exploration, Inc | Pauls Valley, OK 73075 | Oil & Gas Operator | Mar 2008 |
| 5978 | Climax Oil Co LLC | Comanche, OK 73529-7715 | Oil Operator | Nov 2025 |
| 5979 | Clinch Drilling Company | | Oil & Gas Operator | Jan 2000 |
| 5980 | Clindco Inc | Bartlesville, OK 74006-6213 | Oil & Gas Operator | Oct 2019 |
| 5981 | Cline Oil Inc | Bradford, PA 16701 | Oil & Gas Operator | Dec 2025 |
| 5982 | Cline Production Company | Billings, MT 59104 | Oil & Gas Operator | Dec 2025 |
| 5983 | Clint H. Woodington | | Oil Operator | Dec 1994 |
| 5984 | Clinton Bowers Estate | Manhatten, KS 66502 | Oil Operator | Dec 1998 |
| 5985 | Clinton Gas Marketing Inc | Columbus, OH 43214 | Oil & Gas Operator | Dec 1988 |
| 5986 | Clinton Oil Company | Wichita, KS 67202 | Oil & Gas Operator | Apr 1980 |
| 5987 | Clinton Petroleum Co Inc | Randolph, OH 44265 | Oil & Gas Operator | Dec 2009 |
| 5988 | Clinton Producti | | Oil Operator | Dec 1989 |
| 5989 | Clinton Production, Inc. | Wichita, KS 67206 | Oil & Gas Operator | Aug 2025 |
| 5990 | Clinton Public Works Authority | Clinton, OK 73601 | Oil & Gas Operator | May 2023 |
| 5991 | Clinton, Orville L., Jr. | Paola, KS 66071 | Oil Operator | Apr 2005 |
| 5992 | Clipper Operating Co., Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jan 2000 |
| 5993 | CLK Energy Partners, LLC | | Oil & Gas Operator | Aug 2018 |
| 5994 | CLM Oil Production Inc | Bartlesville, OK 74006-4417 | Oil & Gas Operator | Dec 2025 |
| 5995 | CLM Operating | Graham, TX 76450 | Oil & Gas Operator | Aug 2017 |
| 5996 | Cloer VIrgil R | Oklahoma City, OK 73121 | Oil & Gas Operator | Apr 1993 |
| 5997 | Clofas Case Oil Co. | | Oil & Gas Operator | Dec 2025 |
| 5998 | Close, Bryan H. | Shamrock, TX 79079 | Gas Operator | Mar 2026 |
| 5999 | Clothier, David W. | Eastborough, KS 67206 | Oil & Gas Operator | Dec 2019 |
| 6000 | Cloud Peak Operating LLC | Casper, WY 82601 | Oil Operator | Dec 2025 |