Biography

Born in South Dakota, the son of a railway and factory worker, Hagerthy arrived in Glendale, California at the age of four when his family moved there. After graduating from school, he studied at Glendale City College and gained his first acting experience in amateur school and college plays. While on stage, he was 'talent scouted', invited to an audition at Warner Brothers and subsequently recruited for a part in the crime drama I Was a Communist for the F.B.I. (1951). Hagerthy then briefly worked as an ambulance driver before being conscripted into the army. Initially trained as an infantryman at Fort Ord, he was later seconded to a television subsidiary of the army and became involved in the production of the syndicated TV show The Gray Ghost (1957) (the story of Confederate cavalry officer John S. Mosby and his battalion, known as Mosby's Raiders). He made a guest appearance in a 1957 episode.

Hagerthy became best-known as co-star of the TV series Sky King (1951) as 'Clipper', the lead character's nephew. He also featured in the pilot episode of The Beverly Hillbillies (1962) as the geologist who first discovers oil on the Clampett's property. On the big screen, Hagerthy romanced Janice Rule as a bashful Air Force pilot in the musical Starlift (1951) and played a naive juvenile who falls in with criminals in City That Never Sleeps (1953). His TV credits have included more than a fair share of westerns (he was an adept horseman from childhood), among them Annie Oakley (1954), Tales of Wells Fargo (1957), Gunsmoke (1955), Have Gun - Will Travel (1957), Rawhide (1959) and The High Chaparral (1967). He later said in an interview "I played eighteen years old for 10 years. I always looked young, and I guess I still do."

Hagerthy retired from acting in 1968 and eventually worked in management for a real estate company in Century City, Los Angeles. He later set up his own agency in Orange County.
- IMDb mini biography by: I.S.Mowis