The title of the original screenplay was "The Last Ritual". It was changed after the script's heavy religious theme was axed, and the story was rigorously revised.
The eerie whistling motif heard in Brad Fiedel's music score is a reference to the rescue whistle that Warren (Gregg Henry) carries in the film.
The movie's producers originally wanted to edit the rope bridge from the production in hopes of saving money and time. Jeff Lieberman argued to keep the rope bridge part of the movie, as it would be a unique element that would help the movie create more excitement, and thus be more successful. Lieberman won out and the rope bridge was kept. Later, during distribution, one U.K. poster for this movie featured artwork of the characters crossing the rope bridge.
Despite its authentic, weathered appearance, the "old" church house used in the film was built for the production.