The helicopter used in this filming is a 1966 Bell 47J-2A (Registration number N8552F Serial number 3705). It is still operational and flying with an airworthiness certificate good through August 2019.
Barney Phillips says "If there is some such thing as an alien in this country, we'll find him." This is an epic line because in Will the Real Martian Please Stand Up? (1961) he plays an alien.
Both Roy Thinnes and John Lasall (Bob Ferrara) were in the Dark Shadows franchise. Lasall was Dr. Peter Guthrie on the daytime serial, Dark Shadows (1966) during the Phoenix storyline, the one before the introduction of vampire Barnabas Collins into the series. Thinnes played Roger Collins and Reverend Trask on the prime time series, Dark Shadows (1991).