In 1978, Sean S. Cunningham set out to make a "real scary movie" called Long Night at Camp Blood. Then it hit him: the film should instead be called Friday the 13th. Like any good director, he promptly hired a New York ad agency to develop a logo for the unmade film and bought a full-page ad in Variety.
While scouting locations, Cunningham stumbled across a boy scout camp in northern New Jersey called No-Be-Bo-Sco. He rented the camp and proceeded to make his film. Buried in this real-life Camp Crystal Lake's site is one small reference to this fact. The boy scouts and Cunningham had rung the death knell of casual sex among promiscuous 70s youths, at least in any outdoor setting.