| 1801 | Coleville Petroleum Company | McAllen, TX 78503 | Oil & Gas Operator | Mar 1996 |
| 1802 | Coley, H. B. | Corsicana, TX 75110 | Oil & Gas Operator | Oct 2000 |
| 1803 | Coley, Thomas | Graham, TX 76450 | Oil & Gas Operator | Sep 2026 |
| 1804 | Colgate Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Apr 2024 |
| 1805 | Colgrade Investment Corp. | | Oil Operator | Apr 2004 |
| 1806 | Collet Oil Ventures Inc | Denver, CO 80217 | Oil & Gas Operator | Jun 2004 |
| 1807 | Collier Oil Field Services Inc | Iowa Park, TX 76367 | Oil & Gas Operator | Sep 2026 |
| 1808 | Collier Oil Prop | | Oil Operator | Apr 1987 |
| 1809 | Collier Petroleum Corporation | Taloga, OK 73667-9644 | Oil & Gas Operator | Jan 2013 |
| 1810 | Collier, Scott Inc. | Holliday, TX 76366 | Oil Operator | May 2003 |
| 1811 | Collier, W. D. Ranch | Post, TX 79356 | Oil & Gas Operator | Jan 2012 |
| 1812 | Collin C W Jr | | Oil Operator | Oct 2015 |
| 1813 | Collin Oil Operations LLC | | Oil Operator | Jun 2026 |
| 1814 | Collins & Ware, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 1815 | Collins Associates Inc | | Oil & Gas Operator | Mar 1987 |
| 1816 | Collins C R And Collins F Dba Collins Brothers Oil | | Oil & Gas Operator | Jul 2008 |
| 1817 | Collins Dillard Dba Dilco Oil Company | Mangum, OK 73554-4029 | Oil & Gas Operator | Feb 2026 |
| 1818 | Collins John B | | Oil Operator | Sep 1994 |
| 1819 | Collins Oil & Gas Corp | Roswell, NM 88202 | Oil & Gas Operator | Jul 2017 |
| 1820 | Collins Oil Co. | Bartlesville, OK 74006 | Oil & Gas Operator | Dec 2025 |
| 1821 | Collins Oil Comp | | Oil Operator | Apr 1995 |
| 1822 | Collins Oil, LLC | Ellinwood, KS 67526 | Oil Operator | Apr 2026 |
| 1823 | Collins Petroleum Inc | Bartlesville, OK 74006-7024 | Oil & Gas Operator | Apr 2005 |
| 1824 | Collins Resources, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Mar 2011 |
| 1825 | Collins, Dave | Bolivar, NY 14715 | Oil & Gas Operator | Dec 2025 |
| 1826 | Collins, David A And Cole, Alexander B. | Bolivar, NY 14715 | Oil & Gas Operator | Dec 2025 |
| 1827 | Collins, Paul | | Oil & Gas Operator | Dec 2021 |
| 1828 | Collins, Stephen M | | Oil Operator | May 2026 |
| 1829 | Collins-McGregor Operating Company | Marietta, OH 45750 | Oil & Gas Operator | Dec 2025 |
| 1830 | Colo Construction Co., Inc. | Abilene, TX 79602 | Oil Operator | Apr 2004 |
| 1831 | Colo Exploration Company, Inc. | Benbrook, TX 76126 | Oil & Gas Operator | Sep 2026 |
| 1832 | Cologne Production Company | San Antonio, TX 78209 | Oil & Gas Operator | Nov 2014 |
| 1833 | Colonial Corporation | St Simons Island, GA 31522 | Oil & Gas Operator | Dec 2000 |
| 1834 | Colonial Energy Company Inc | Garland, TN 75045 | Oil & Gas Operator | Apr 2015 |
| 1835 | Colonial Resources LLC | Edmond, OK 73003-3207 | Oil & Gas Operator | Aug 2019 |
| 1836 | Colorado Bluebonnet Energy Corp. | Englewood, CO 80112 | Oil & Gas Operator | Feb 2001 |
| 1837 | Colorado Crude E | | Oil Operator | Jan 1986 |
| 1838 | Colorado Drilling Company | Grand Junction, CO 81501 | Oil Operator | Jan 1990 |
| 1839 | Colorado Gas Compression Inc | Longmont, CO 80501-5868 | Oil & Gas Operator | Aug 2013 |
| 1840 | Colorado Interstate Gas Co | Colorado Springs, CO 80944 | Oil & Gas Operator | Jul 2004 |
| 1841 | Colorado Interstate Gas Company LLC | Colorado Springs, CO 80944 | Oil & Gas Operator | May 2026 |
| 1842 | Colorado Oil & G | | Oil & Gas Operator | Oct 1987 |
| 1843 | Colorado Oil & Gas Corporation | | Oil & Gas Operator | Sep 1984 |
| 1844 | Colorado Oil Co., Inc. | | Oil & Gas Operator | Dec 1977 |
| 1845 | Colorado Pica Petro Corp | Cortez, CO 81321 | Oil & Gas Operator | Apr 2007 |
| 1846 | Colorado-Swanson Landing Oil & Gas, LLC | Kilgore, TX 75663 | Oil Operator | Sep 2026 |
| 1847 | Colossus Operating LLC | Kalispell, MT 59901 | Oil Operator | May 2026 |
| 1848 | Colpitt Brothers Oil | Collinsville, OK 74021 | Oil & Gas Operator | Apr 2020 |
| 1849 | Colpitt Brothers Operating Co | Collinsville, OK 74021 | Oil & Gas Operator | Jun 2026 |
| 1850 | Colpitt C H Drilling Co LLC | Collinsville, OK 74021-7107 | Oil Operator | May 2026 |
| 1851 | Colpitt Chas H Drilling Co | Collinsville, OK 74021-7105 | Oil & Gas Operator | Mar 2012 |
| 1852 | Colt Energy Inc | Iola, KS 66749 | Oil & Gas Operator | Apr 2026 |
| 1853 | Colt Energy Inco | | Oil & Gas Operator | Dec 1996 |
| 1854 | Colt Oil & Gas Co. | Abilene, TX 79601 | Oil Operator | Apr 2004 |
| 1855 | Colt Oil Company | Andrews, TX 79714 | Oil & Gas Operator | Feb 1996 |
| 1856 | Colt Oil LLC | Sapulpa, OK 74066-1010 | Oil Operator | May 2026 |
| 1857 | Colt Production Corp. Inc. | | Oil & Gas Operator | Jul 1996 |
| 1858 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 1859 | Colter Operating Co | Horseshoe Bay, TX 78654 | Oil & Gas Operator | Nov 1997 |
| 1860 | Coltharp, Edward H | | Oil & Gas Operator | Dec 1970 |
| 1861 | Colton Limited Liability Co | | Oil & Gas Operator | Sep 2023 |
| 1862 | Coltrane Charles | | Oil Operator | Dec 1980 |
| 1863 | Columbia Energy Properties, Inc. | Baytown, TX 77521 | Oil & Gas Operator | Jul 2004 |
| 1864 | Columbia Gas Dev. Corp. | | Oil & Gas Operator | Apr 1996 |
| 1865 | Columbia Gas Development | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 1866 | Columbia Gas Development Corp. | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 1867 | Columbia Gas Trans Corp | | Gas Operator | Dec 1987 |
| 1868 | Columbia Gas Transmission, LLC | Charleston, WV 25314 | Oil & Gas Operator | Dec 2021 |
| 1869 | Columbia Gulf Transmission Co. | | Oil Operator | Dec 2014 |
| 1870 | Columbia Gulf Transmission Company, LLC | | Oil Operator | Jan 2025 |
| 1871 | Columbia Minerals Corp., Inc. | | Oil & Gas Operator | May 1996 |
| 1872 | Columbia Natural Res Inc | Charleston, WV 25362-0070 | Gas Operator | Dec 2008 |
| 1873 | Columbia Natural Resources, LLC | Charleston, WV 23502 | Oil & Gas Operator | Dec 2021 |
| 1874 | Columbia Oil Company, Inc | | Oil & Gas Operator | Jan 2025 |
| 1875 | Columbia Petrole | | Oil Operator | Sep 1988 |
| 1876 | Columbia Petroleum Corp. | | Oil & Gas Operator | Jun 1982 |
| 1877 | Columbia Petroleum LLC | Oyster Bay, NY 11771 | Oil & Gas Operator | Feb 2025 |
| 1878 | Columbia Petroleum, LTD. | Lewistown, MT 59457 | Oil Operator | Jun 2026 |
| 1879 | Columbia Production Company | Edmond, OK 73083 | Oil & Gas Operator | May 2020 |
| 1880 | Columbian Production Corporation | Topeka, KS 66601 | Oil Operator | Oct 1999 |
| 1881 | Columbian Servic | | Oil & Gas Operator | Nov 1993 |
| 1882 | Columbian Services C | | Oil Operator | Jan 1992 |
| 1883 | Columbian Services Corporation | Topeka, KS 66603 | Gas Operator | Dec 2009 |
| 1884 | Columbine Associates | | Oil & Gas Operator | Jun 2026 |
| 1885 | Columbine Exploration Corp | Englewood, CO 80111 | Oil & Gas Operator | Aug 1998 |
| 1886 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 1887 | Columbus Energy, LLC | Houston, TX 77046 | Oil & Gas Operator | Sep 2026 |
| 1888 | Columbus III Production LC | | Oil Operator | Oct 2003 |
| 1889 | Columbus Oil And Gas LLC | | Oil Operator | Oct 2020 |
| 1890 | Columbus Oil Company | Seminole, OK 74868 | Oil & Gas Operator | Jun 2026 |
| 1891 | Columbus Oilfield Explor Co | Powell, OH 43065-9315 | Gas Operator | Dec 2004 |
| 1892 | Columbus Oilfield Exploration Company | Columbus, OH 43220 | Oil & Gas Operator | Dec 2013 |
| 1893 | Columbus Production Inc | | Oil & Gas Operator | Mar 2005 |
| 1894 | Comac Well Service, Inc. | Borger, TX 79008 | Oil & Gas Operator | Mar 2008 |
| 1895 | Comal Operating LLC | Fredericksbrg, TX 78624 | Oil & Gas Operator | Sep 2026 |
| 1896 | Comanche Drilling Company | Cut Bank, MT 59427 | Oil & Gas Operator | Jun 2026 |
| 1897 | Comanche Exploration Co LLC | Oklahoma City, OK 73116-7334 | Oil & Gas Operator | Jun 2026 |
| 1898 | Comanche Exploration Company | Oklahoma City, OK 73120-2797 | Oil & Gas Operator | Feb 2007 |
| 1899 | Comanche Oil & Gas Corp | Salt Lake City, UT 84107-3075 | Oil & Gas Operator | May 2005 |
| 1900 | Comanche Oil And Service, LLC | | Oil Operator | May 2026 |