Devil's Tower

LOL, I was right about to say what others already have, that this reminded me of the alien mountain! Been a while since I saw Close Encounters, but I think it's a classic. It's not just about aliens, more like a man who's convinced there are aliens out there and in the process "alienating" himself from the rest of his family because they think he's gone mad. One scene I remember in particular is the man carving out this mountain from mashed potato in a family dinner scene