Much of the movie was filmed in Tuolumne County, California in June 1978 as a Dan Curtis Productions project. Tuolumne County has been the location of well over 100 movies and tv shows including High Noon, Back To The Future and Pale Rider to Bonanza, Little House On The Prairie and Highway To Heaven. Railtown 1897 state park in Jamestown is the home of train engine "Number 3", which has been seen in many classic movies and tv shows. Columbia state park has been scene in lots of movies, most notably "High Noon" with Gary Cooper and Grace Kelly. The house used as Kelly's home in the film actually belonged to a teacher at the local elementary school as it had a classic look that producers loved and wanted to use in the film.