The Ketchikan airline depicted, Ellis Air, was an authentic Ketchikan company, founded by Bob Ellis in 1936. The aircraft shown in the movie is a Grumman G-21 Goose amphibious craft. If you look closely at the bottom of the plane you can see the wheels, which were used for ground landings. Ellis Air merged with Alaska Coastal Airlines in 1962, and this concern was itself taken over by Alaska Airlines in 1968.
Richard Deacon, who played Mel Cooley in The Dick Van Dyke Show (1961), has a bit part as a bartender about 15 minutes into the movie.