evidence: Close Encounters of the Third Kind and Devils Tower, Wyoming Devils Tower is a National Monument situated in Wyoming and featured in the climax of the movie Close Encounters of the Third Kind. Devils Tower, located in Crook County, Wyoming, was the first natural formation in the United States to be declared a national monument in 1906. Part of the Black Hills mountain range, the monolith was formed from cooled magma exposed through erosion and stands at 1,267 feet tall.