Devil's Tower
44.590379°N 104.719759°W

Note the columnar jointing.

The precise places near Devil's Tower where a large part of the movie was filmed need to be located more exactly.

Close Encounters of the Third Kind

Close Encounters of the Third Kind (often referred to as Close Encounters or CE3K) is a 1977 science fiction-drama written and directed by Steven Spielberg and features actors Richard Dreyfuss, François Truffaut, Melinda Dillon, Teri Garr, Bob Balaban, and Cary Guffey. It tells the story of Roy Neary, a lineman in Indiana, whose life changes after a close encounter with an unidentified flying object (UFO).

• http://en.wikipedia.org/wiki/Close Encounters of the Third Kind