| 6001 | Clayton W. Williams, Jr. | | Oil & Gas Operator | Sep 1986 |
| 6002 | Clayton W. Williams, Jr., Inc. | | Oil & Gas Operator | May 1993 |
| 6003 | Clayton Williams Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2017 |
| 6004 | CLC Operations Inc | Midland, TX 79701 | Oil & Gas Operator | Mar 1997 |
| 6005 | Clean Energy Exploration & Production LLC | Norristown, PA 19403 | Gas Operator | Feb 2025 |
| 6006 | Clean Energy Systems Placerita Inc. | | Oil & Gas Operator | Dec 2024 |
| 6007 | Clean Gas, Inc | Hindman, KY 41822 | Oil & Gas Operator | Dec 2023 |
| 6008 | Clean Oil LLC | Ada, OK 74820 | Oil & Gas Operator | Jan 2025 |
| 6009 | Cleantex Oilfield Services, LLC | Tyler, TX 75702 | Oil Operator | Apr 2025 |
| 6010 | Clear Brooke Ranches, LLC | Fort Worth, TX 76179 | Oil & Gas Operator | Apr 2025 |
| 6011 | Clear Creek Energy LLC | | Oil & Gas Operator | Dec 2021 |
| 6012 | Clear Creek Exploration LLC | Fredonia, KS 66736 | Gas Operator | Apr 2011 |
| 6013 | Clear Creek Oil Co | Nova, OH 44859 | Oil & Gas Operator | Dec 2018 |
| 6014 | Clear Creek Royalty LLC | Tulsa, OK 74137 | Oil & Gas Operator | Jul 2023 |
| 6015 | Clear Fork Gas Company | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 6016 | Clear Fork, Incorporated | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 6017 | Clear Lake Oil Co. | | Oil Operator | Jan 2025 |
| 6018 | Clear Water Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2025 |
| 6019 | Clearfield Energy Resources & Management Inc. | | Oil & Gas Operator | Dec 1998 |
| 6020 | Clearfork Operating LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2011 |
| 6021 | Clearfork Petroleum Inc. (A) | Lubbock, TX 79408 | Oil & Gas Operator | Apr 2025 |
| 6022 | Clearfork Production, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2018 |
| 6023 | Clearly Petroleum, LLC | Houston, TX 77086 | Oil & Gas Operator | Jun 2020 |
| 6024 | Cleary Exploration LLC | Oklahoma City, OK 73112-7221 | Oil & Gas Operator | Oct 2014 |
| 6025 | Cleary Jo Anne | Saint Louis, OK 74866 | Oil Operator | Jan 2025 |
| 6026 | Cleary Jon C | Lancaster, OH 43130 | Gas Operator | Dec 2022 |
| 6027 | Cleary Petroleum Corporation | Edmond, OK 73083 | Oil & Gas Operator | Jul 2019 |
| 6028 | Cleaveland Price Inc | Trafford, PA 15085-9550 | Gas Operator | Dec 2024 |
| 6029 | Cleaver Loraine | | Oil Operator | Dec 1996 |
| 6030 | Cleaver, Loraine G. (Deceased) Estate | Iola, KS 66749 | Oil Operator | Nov 2009 |
| 6031 | Cleere Operating LLC | Shawnee, OK 74804-2610 | Oil Operator | Dec 2024 |
| 6032 | Clem Energy LLC | | Oil & Gas Operator | Dec 2021 |
| 6033 | Clements Energy, Inc. | | Oil & Gas Operator | Oct 1987 |
| 6034 | Clements Exploration Co | Oklahoma City, OK 73132-5922 | Oil & Gas Operator | Jan 2006 |
| 6035 | Clements Operating Company, Inc. | Luling, TX 78648 | Oil & Gas Operator | Aug 2003 |
| 6036 | Clements-B & MCK - Luffey | | Gas Operator | Apr 1979 |
| 6037 | Clemishire Bryan | Hominy, OK 74035 | Oil & Gas Operator | Nov 2014 |
| 6038 | Clemishire Don | Hominy, OK 74035 | Oil & Gas Operator | Jan 2025 |
| 6039 | Clemishire Mark | Hominy, OK 74035 | Oil Operator | Jan 2025 |
| 6040 | Clemishire, Jerry L | | Oil & Gas Operator | Jan 2025 |
| 6041 | Clemons, Tony W. | Minden, LA 71055 | Oil & Gas Operator | Dec 2016 |
| 6042 | Clemshire Bob | Hominy, OK 74035 | Oil & Gas Operator | Jan 2025 |
| 6043 | Clemshire Drilling Company | Tulsa, OK 74105 | Oil Operator | Jan 2025 |
| 6044 | Clendening, John A | | Oil Operator | Dec 2021 |
| 6045 | Cleo Oil, Inc. | Olney, TX 76374 | Oil & Gas Operator | May 1997 |
| 6046 | Cleveland Cameron Gas Co | Waynesburg, PA 15370-1437 | Gas Operator | Dec 2024 |
| 6047 | Cleveland Oil & Gas | Wichita Falls, TX 76308 | Oil Operator | Apr 2025 |
| 6048 | Cleveland Oil Company,L.L.C.,The | Midland, TX 79702 | Oil & Gas Operator | Sep 1999 |
| 6049 | Cleveland Production Company | Summit, MS 39666 | Oil & Gas Operator | Jul 1999 |
| 6050 | Cleveland Rod & Tracy | Elmore City, OK 73433-9467 | Oil & Gas Operator | Jul 2023 |
| 6051 | Click Betty | Stigler, OK 74462-0081 | Oil & Gas Operator | Feb 2016 |
| 6052 | Click Corp | Monroe, LA 71207 | Oil & Gas Operator | Jan 2025 |
| 6053 | Click Energy Company | Houston, TX 77269 | Oil & Gas Operator | Apr 2025 |
| 6054 | Click Robert R | Dallas, TX 75231 | Oil & Gas Operator | Nov 1995 |
| 6055 | Clide Oil Corp. | Iraan, TX 79744 | Oil & Gas Operator | Nov 2015 |
| 6056 | Clifford & Scott McKeever | Clarksburg, PA 15725 | Gas Operator | Dec 2024 |
| 6057 | Clifford C. Or Mary A. Terry | Dadeville, AL 36853 | Oil Operator | Feb 2003 |
| 6058 | Clifford Resourc | | Oil & Gas Operator | Mar 1989 |
| 6059 | Clifford Resources Inc | Oklahoma City, OK 73120 | Oil & Gas Operator | Jul 2015 |
| 6060 | Cliffs Drilling Company | | Oil & Gas Operator | Dec 1984 |
| 6061 | Cliffs Oil And Gas Company | | Oil & Gas Operator | Oct 1997 |
| 6062 | Cliffwood Production Co. | Houston, TX 77090 | Oil & Gas Operator | Aug 2013 |
| 6063 | Clift Cary E | Chickasha, OK 73018-6305 | Oil & Gas Operator | Sep 2024 |
| 6064 | Clifton & Associates Inc | Tulsa, OK 74133 | Oil & Gas Operator | May 2020 |
| 6065 | Clifton Consulting Inc | Piedmont, OK 73078-0180 | Gas Operator | Jan 2025 |
| 6066 | Clifton Oil | Muenster, TX 76252 | Oil & Gas Operator | Mar 2006 |
| 6067 | Clifton, B.W. | Graham, TX 76450 | Oil & Gas Operator | Mar 2000 |
| 6068 | Clifton, Joe B. Exploration, Inc | Pauls Valley, OK 73075 | Oil & Gas Operator | Mar 2008 |
| 6069 | Clinch Drilling Company | | Oil & Gas Operator | Jan 2000 |
| 6070 | Clindco Inc | Bartlesville, OK 74006-6213 | Oil & Gas Operator | Oct 2019 |
| 6071 | Cline Oil And Gas Company | Santa Fe, NM 87501 | Oil & Gas Operator | Sep 1994 |
| 6072 | Cline Oil Inc | Bradford, PA 16701 | Oil & Gas Operator | Dec 2024 |
| 6073 | Cline Production Company | Billings, MT 59104 | Oil & Gas Operator | Feb 2025 |
| 6074 | Clint H. Woodington | | Oil Operator | Dec 1994 |
| 6075 | Clinton Bowers Estate | Manhatten, KS 66502 | Oil Operator | Dec 1998 |
| 6076 | Clinton Gas Marketing Inc | Columbus, OH 43214 | Oil & Gas Operator | Dec 1988 |
| 6077 | Clinton Oil Co | Wichita, KS 67202 | Oil & Gas Operator | Apr 1980 |
| 6078 | Clinton Petroleum Co Inc | Randolph, OH 44265 | Oil & Gas Operator | Dec 2009 |
| 6079 | Clinton Producti | | Oil Operator | Dec 1989 |
| 6080 | Clinton Production, Inc. | Wichita, KS 67206 | Oil & Gas Operator | Dec 2024 |
| 6081 | Clinton Public Works Authority | Clinton, OK 73601 | Oil & Gas Operator | May 2023 |
| 6082 | Clinton, Orville L., Jr. | Paola, KS 66071 | Oil Operator | Apr 2005 |
| 6083 | Clipper Operating Co., Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jan 2000 |
| 6084 | CLK Energy Partners, LLC | | Oil & Gas Operator | Aug 2018 |
| 6085 | CLM Oil Production Inc | Bartlesville, OK 74006-4417 | Oil & Gas Operator | Jan 2025 |
| 6086 | CLM Operating | Graham, TX 76450 | Oil & Gas Operator | Aug 2017 |
| 6087 | Cloer VIrgil R | Oklahoma City, OK 73121 | Oil & Gas Operator | Apr 1993 |
| 6088 | Clofas Case Oil Co. | | Oil & Gas Operator | Dec 2024 |
| 6089 | Close, Bryan H. | Shamrock, TX 79079 | Gas Operator | Apr 2025 |
| 6090 | Clothier, David W. | Eastborough, KS 67206 | Oil & Gas Operator | Dec 2019 |
| 6091 | Cloud Peak Operating LLC | Casper, WY 82601 | Oil Operator | Feb 2025 |
| 6092 | Clovelly DRLG & Dev Co Inc | | Oil & Gas Operator | Oct 1983 |
| 6093 | Clovelly Oil Co. LLC | | Oil & Gas Operator | Nov 2024 |
| 6094 | Clovelly Oil Co., Inc. | | Oil & Gas Operator | Nov 2008 |
| 6095 | Clovelly Oil Co., Inc. - Ripco | | Oil & Gas Operator | Nov 1991 |
| 6096 | Clover Energy Corp | | Oil & Gas Operator | May 1980 |
| 6097 | Clover Oil Company | | Oil Operator | Dec 2024 |
| 6098 | Clover Production Company | Sourlake, TX 77659 | Oil & Gas Operator | Apr 2025 |
| 6099 | Clowser Well Service, Inc. | | Oil & Gas Operator | Dec 2021 |
| 6100 | CLR Gauging Corp. | Tuleta, TX 78162 | Oil & Gas Operator | Apr 2025 |