The DJ’s ( Cleavon Little ) radio station scenes were from the Goldfield Hotel, Goldfield Nevada. It’s supposedly one of the most haunted places in the USA.
https://www.onlyinyourstate.com/nevada/most-terrifying-nevada-ghost-story-is-truly-chilling/
I've been to Cisco, Utah, (Cisco, CA in the movie), many times. It's a weird, spooky place as well.
Always wanted to visit Goldfield.