| 1901 | Harris Oil & Gas Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2016 |
| 1902 | Harris, David | Toronto, KS 66777 | Oil Operator | Sep 2025 |
| 1903 | Harrison Oil | Lindsay, OK 73052 | Oil & Gas Operator | Nov 2014 |
| 1904 | Harrison, Mark V. | Madison, KS 66860 | Oil Operator | Jul 1995 |
| 1905 | Hart Energies, LLC | Tulsa, OK 74133 | Oil & Gas Operator | Dec 2016 |
| 1906 | Hart, Nick And Connie | Paola, KS 66071 | Oil Operator | Sep 2025 |
| 1907 | Hartman Oil Company Inc | Wichita, KS 67206 | Oil & Gas Operator | Sep 2025 |
| 1908 | Hartman W L Trus | | Oil Operator | Jun 1992 |
| 1909 | Harvest Energy Company | Englewood, CO 80110 | Oil & Gas Operator | Jun 1997 |
| 1910 | Hasada Industrie | | Oil & Gas Operator | Jul 1995 |
| 1911 | Hat Creek Cattle Company, A General Partnership | Paola, KS 66071 | Oil Operator | Aug 2016 |
| 1912 | Haul-Pac, Inc. | Hiawatha, KS 66434 | Oil Operator | Aug 2025 |
| 1913 | Haven Oil & Gas | Hutchinson, KS 67504 | Oil & Gas Operator | Mar 2009 |
| 1914 | Hawkeye Oil | | Oil & Gas Operator | Jun 2007 |
| 1915 | Hawkins Oil & Ga | | Oil & Gas Operator | Jun 1995 |
| 1916 | Hawkins Oil & Gas Company | Richardson, TX 75080 | Oil & Gas Operator | Feb 2026 |
| 1917 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 1918 | Hawkins Oil, L.L.C. | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2025 |
| 1919 | Hawkins, James F. | Tulsa, OK 74103 | Oil Operator | Dec 2019 |
| 1920 | Hawley John B Jr | | Gas Operator | Dec 1983 |
| 1921 | Hawn Petroleum I | | Oil Operator | Jun 1989 |
| 1922 | Hayden Operating | | Oil & Gas Operator | Sep 2025 |
| 1923 | Hayes Oil & Gas LLC | Attica, KS 67009 | Oil & Gas Operator | Sep 2025 |
| 1924 | Hayes Well Servi | | Oil & Gas Operator | Feb 1992 |
| 1925 | Haynie Robert L | | Gas Operator | Jan 2004 |
| 1926 | Hays Oil Field S | | Oil Operator | Nov 1988 |
| 1927 | Hazen, Paul D. | Great Bend, KS 67530 | Oil Operator | Nov 1990 |
| 1928 | Hazen, Ty Anthony | Lyons, KS 67554 | Oil Operator | Sep 2025 |
| 1929 | HB Energy LLC | Wellsville, KS 66092 | Oil Operator | Sep 2025 |
| 1930 | HB Oil Company | Abilene, TX 79602 | Oil & Gas Operator | Jun 2023 |
| 1931 | HD Well Services LLC | Wellsville, KS 66092 | Oil Operator | Sep 2025 |
| 1932 | HDH Resources, Inc. | Wilmore, KS 67155 | Oil & Gas Operator | Jul 2025 |
| 1933 | Headington Canada Corp. | Dallas, TX 75231 | Gas Operator | Jun 2000 |
| 1934 | Heady, Harold | Parsons, KS 67357 | Gas Operator | Aug 2016 |
| 1935 | Heartland Enterprises, Incorporated | Phillipsburg, KS 67661 | Oil Operator | May 2005 |
| 1936 | Heartland Oil & Gas Inc. | Gypsum, KS 67448 | Gas Operator | Jun 2011 |
| 1937 | Heat Can Oil, LLC | Chanute, KS 66720 | Oil Operator | Jun 2009 |
| 1938 | Heat Waves Hot Oil Service LLC | Denver, CO 80202 | Oil Operator | Jun 2011 |
| 1939 | Heath, Mark | Leoti, KS 67861 | Oil Operator | Nov 2009 |
| 1940 | Hedrick, Thomasine | Severy, KS 67137 | Oil Operator | May 2011 |
| 1941 | Heger J J & Asso | | Oil Operator | Jun 1983 |
| 1942 | Hegwald, Jacob L. | Humboldt, KS 66748 | Oil Operator | Nov 2019 |
| 1943 | Helberg Oil Comp | | Oil Operator | Mar 1995 |
| 1944 | Helbing & Robert | | Oil & Gas Operator | Feb 1991 |
| 1945 | Held By Producti | | Oil & Gas Operator | Feb 1995 |
| 1946 | Hellar Drilling | | Oil & Gas Operator | Jan 1994 |
| 1947 | Hellar Drilling Company, Inc. | Wichita, KS 67208 | Oil & Gas Operator | Jan 2009 |
| 1948 | Heller Phillip & Charlene | Columbia, MO 65201 | Oil & Gas Operator | Nov 2025 |
| 1949 | Helm Energy Company | Tulsa, OK 74133 | Oil Operator | Sep 2025 |
| 1950 | Helmerich & Payn | | Oil & Gas Operator | Aug 1995 |
| 1951 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Nov 2025 |
| 1952 | Helsel, Allan J | South Haven, KS 67140 | Oil Operator | Aug 2025 |
| 1953 | Hembree Oil Production, LLC | Great Bend, KS 67530 | Oil Operator | Sep 2025 |
| 1954 | Hembree Robert F | | Oil Operator | Dec 2009 |
| 1955 | Henderson, Chris | Pawhuska, OK 74056 | Oil Operator | Dec 2009 |
| 1956 | Henke, Elden H. | Lost Springs, KS 66859 | Oil & Gas Operator | Feb 1996 |
| 1957 | Hennessy Oil Com | | Oil Operator | Mar 1991 |
| 1958 | Hensley Oil Company LLC | Arkansas City, KS 67005 | Oil Operator | Sep 2025 |
| 1959 | Hensley, Cloide J. & Hazel M. | Arkansas City, KS 67005 | Oil Operator | Sep 2001 |
| 1960 | Heritage Oil L.L.C. | Hays, KS 67601 | Oil Operator | Sep 2025 |
| 1961 | Herman Krug - Oil Operations | | Oil Operator | Sep 2025 |
| 1962 | Herman L. Loeb LLC | Lawrenceville, IL 62439 | Oil & Gas Operator | Sep 2025 |
| 1963 | Herman Lang Oil And Gas Co. | | Oil & Gas Operator | Dec 1992 |
| 1964 | Hermreck Oil Com | | Oil & Gas Operator | Aug 1996 |
| 1965 | Hermreck Oil Company | | Oil Operator | Nov 2024 |
| 1966 | Herndon Drilling | | Oil & Gas Operator | May 1988 |
| 1967 | Hertel Oil Company | | Oil Operator | Nov 2018 |
| 1968 | Hertel Oil Company LLC | Hays, KS 67601 | Oil Operator | Sep 2025 |
| 1969 | Hess Oil Company | McPherson, KS 67460 | Oil & Gas Operator | Sep 2025 |
| 1970 | Hesse Petroleum Co.,L.L.C. | Wichita, KS 67208 | Oil & Gas Operator | Sep 2025 |
| 1971 | Hessert Edward C | | Oil & Gas Operator | Sep 1993 |
| 1972 | Hessert Loc Inc | Carl Junction, MO 64834 | Oil Operator | Dec 2009 |
| 1973 | Hett Oil & Gas, LLC | Lincolnville, KS 66858 | Oil & Gas Operator | Sep 2025 |
| 1974 | Hewitt Energy Group Inc | Salt Lake City, UT 84111 | Oil & Gas Operator | Apr 2015 |
| 1975 | HG Oil Holdings, LLC | Hoisington, KS 67544 | Oil & Gas Operator | Sep 2025 |
| 1976 | Hi-Kat Petroleum | | Oil Operator | Mar 1990 |
| 1977 | Hi-Kat Petroleum Company | Liberal, KS 67905-1261 | Oil & Gas Operator | May 2014 |
| 1978 | Hibernian Compan | | Oil & Gas Operator | Feb 1991 |
| 1979 | Hicks Exploration, LLC | Dover, OK 73734 | Gas Operator | Dec 2024 |
| 1980 | Hiebert & Wedel | | Oil & Gas Operator | May 1995 |
| 1981 | Hiebert, D. O. Lewis | McPherson, KS 67460 | Oil Operator | Feb 1999 |
| 1982 | Higginbottom Engineering, Inc. | Liberal, KS 67905 | Oil & Gas Operator | Sep 2025 |
| 1983 | Higgins Oil & Ga | | Oil Operator | Apr 1992 |
| 1984 | High Bluff Operating, LLC | Littleton, CO 80161 | Oil & Gas Operator | May 2018 |
| 1985 | High Plains Oil | | Oil Operator | Jun 1989 |
| 1986 | High Plains Production, LLC | Murray, KY 42071 | Oil & Gas Operator | Dec 2024 |
| 1987 | High Point Produ | | Gas Operator | May 1996 |
| 1988 | Hill Oil And Gas Co., Inc. | Overland Park, KS 66213 | Oil Operator | Mar 2020 |
| 1989 | Hillary Oil Comp | | Oil & Gas Operator | Apr 1991 |
| 1990 | Hillenburg Oil C | | Oil Operator | Apr 1994 |
| 1991 | Hillenburg Oil Co., A General Partnership | Broken Arrow, OK 74011 | Oil Operator | Sep 2025 |
| 1992 | Hilliker Oil Com | | Oil Operator | Jul 1984 |
| 1993 | Hilliker Production | Indian Wells, CA 92210 | Oil & Gas Operator | Jul 2007 |
| 1994 | Hilltop Exploration, Inc. | Sedan, KS 67361 | Oil Operator | Jan 2000 |
| 1995 | Himco Oil & Gas Inc | Enid, OK 73702 | Oil & Gas Operator | Nov 2025 |
| 1996 | Hinkle Oil Compa | | Oil & Gas Operator | Nov 1994 |
| 1997 | Hinkle Oil Company | Wichita, KS 67202 | Oil & Gas Operator | Jan 1999 |
| 1998 | Hinks Petroleum Co., Inc. | Wichita, KS 67201 | Oil Operator | May 1999 |
| 1999 | Hirt Farms Incor | | Oil & Gas Operator | Apr 1994 |
| 2000 | Hizey Service & | | Oil Operator | Apr 1994 |