| Surnames | Time Period | Researcher |
| Hacke | 1899 - 1975 | Alan Schulz |
| Haehn | 1978 | Lynn Phillips |
| Hagar | c1942 - ? | Jayne Genter |
| Hall | 1890 - now | Richard Yoachum |
| Hall | 1880s, 1890s | William K. Hall |
| Hall | 1903 - 1922 | Debbie Duley |
| Hamboy | 1798 - ca 1818 | Shirley Gaesser |
| Hamersky | 1875 - now | Michael Hamersky |
| Hamilton | 1940 - 1998 | Kae Potgeter |
| Hammer | 1860 - now | Greg Hammer |
| Hanby | 1874 | Shirley B. Gaesser |
| Hand | 1900 - 1990 | Randy Hand |
| Hansen | 1883 - 1965 | Pam Schmidtberger |
| Hardin | 1930 - now | Charlene Hardin |
| Harkey | 1880's - 1968 | DeLean Holtsclaw |
| Harley | 1925 - 1956 | Sharon Tate |
| Harper | 1874 - 1880 | Connie Leaman |
| Harpstrite | . | Eric Taylor |
| Harris | 1885 - now | Joyce (Routh) Willhoit |
| Hartshorn | 1930 - now | Charlene Hardin |
| Hartzell | 1885 - 1926 | B. Krol |
| Harvey | 1880 - 1950 | Susan Walker |
| Harwick | . | Lee Dowen |
| Harwick | 1920 - now | Jean Bowers |
| Hatfield | 1880 - now | Susan Hatfield |
| Hatton | 1870 - 1900 | Beverly Austin |
| Haverstock | 1900 - 1931 | Debbie Carter |
| Hecker | . | Christ J. Hecker |
| Hecox | 1890 - 1920 | Paula Swope |
| Hein | 1876 | Alan L. Hein |
| Helphrey | c1917 - 1919 | Carolyn Christine Reynolds |
| Helt | 1870 - 1970 | Elaine Chenault |
| Hemphill | 1895 - 1945 | J.K. Rose |
| Hempsmeyer | Veanna Carr | |
| Hemsworth | 1880’s - 1900’s | Edith McDougall |
| Hensley | 1967 | Perry |
| Henson | 1860 - now | Patty Napier |
| Herbert | 1904 - 1981 | Vicki Ames |
| Herman | 1890 - now | L.D. Austin |
| Herring | 1946 - 1984 | Georgiann |
| Hershberger | 1930's | M. Hershberger |
| Hess | 1925 - 1988 | LaRae Rahm |
| Hestwood | 1900 - 1950 | Ike Stanley |
| Hickey | 1890 - now | Cathy Smith |
| Hickson | 1800 - now | Pamela Hickson Banks |
| Hildenbrand | . | Eric Taylor |
| Hilger | 1945 - 1975 | Ike Stanley |
| Hill | 1890 - now | Terry Row |
| Hill | ? - 1920's | David Hill |
| Hillman | 1880's - ? | Wanda Smith |
| Hitchcock | 1910 - now | Richard Hitchcock |
| Hite | 1880's - 1930's | Mary Pollitt |
| Hodgson | c1870 - c1900 | L.D. Cleminshaw |
| Hoefgen | 1880 - now | M. Hoefgen |
| Hoff | 1858 - now | Larry Flowers |
| Hogan | 1930 - 1953 | Barbara Hines |
| Hoisington | 1920 - 1975 | Harriette Jensen |
| Holick | 1900 - now | Ruth Marsh |
| Hollingsworth | 1885 - now | Lorna Marvin |
| Holloway | . | Kathleen Dickens |
| Holwick | 1890 - 1940's | Courtney |
| Honeyman | 1917 - 1945 | Raylene |
| Hoover | 1875 - 1902 | Doyle R. Curtis |
| Hoover | 1869 - now | Julia (Marvin) Royston |
| Hormel | 1830 - now | Luella June Hormel |
| Houck | 1900 - 1963 | Mary Ellen Smith |
| Howard | 1857 - 1934 | Jim Austin |
| Howell | 1900 - now | Jeannie Shires |
| Howland | 1930 | JoAnn C. Hall |
| Huber | ? - now | Amber Ries |
| Hull | 1945 - now | Joan Thomas |
| Hundley | 1938 - now | Larry D. Flowers |
| Hurst | 1880 - now | D.A. Blakemore |
| Hurt | 1900 - 1950 | Kay Hurt |
| Huson | 1870 - 1890 | Shirley W. Beebe |
| Hutchinson | 1915 - 1920 | Terry Steele Curtis |
| Ingmire | 1876 - 1880 | Keith Elmund |
| Irwin | 1970's | Jim Irwin |
| Israel | 1880 - 1910 | Sandy Cotter |
| Ittner | . | Ernest Ittner Jr. |