Last January, we were in Wyoming on one of those snow coach things going into Yellowstone. Our driver was telling about an incident at McDonalds in a small town there. Someone came in holding a drawn weapon for the purposes of holding up the McDonalds cashiers. Our driver laughed and said, "This is Wyoming -- a bunch of the patrons pulled THEIR weapons." End of robbery attempt.
Of course no one was armed on that trip as it's illegal to carry in a National Park.