SOLVED: Young couple visits abandoned hotel/resort

This is an easy one, but I ALWAYS forget the title. I think it is horror because I saw it recently on a "Creature Feature" type show on tv. Almost definitely a 1970's film.

A young couple somehow ends up at what seems to be an abandoned hotel or resort. But they are being watched by a caretaker. I think Soda Springs or something like that was the name of the place.