- Alumni Directory 1874-1908 ; 1959 ; 1963 ; 1967
- List of engineering Students at Ohio Northern University, Ada, Ohio. 1882-1940
- Lawyers of ONU, 1885-1911
- Index to Grade Ledgers, 1871-1908
- Northern - ONU Yearbook 1911-
- ONU Catalogs 1870-
- ONU Genealogical Tips and Tools
- Ohio Northern Alumnus Magazine 1927-2006
Available at the Ada Public Library
- Digital Archives of the Ada Public Library
- Microfilm copies Hardin County Ohio Deed records, 1881-1886
- Will Records, 1901-1912
- Birth Index, 1867-1908
- Death Index, 1868-1908
Family Search - FamilySearch is the largest genealogy organization in the world. Returns results for many types of records in a single search.
Ruther B. Hayes Obituary Index - An index to over 1,500,000 obituaries, death & marriage notices, adn other sources from Ohio from the 1810s to the present day.
Heterick Memorial Library
525 South Main Street
Ada, Ohio 45810
Tuesday: 7:30 a.m.-Midnight
Wednesday: 7:30 a.m.-Midnight
Thursday: 7:30 a.m.-Midnight
Friday: 7:30 a.m.-8 p.m.
Saturday: 10 a.m.-6 p.m.
Sunday: 12 p.m.-Midnight