Two true ones (my wife was a tour guide in the BH):
1: What do you do with Mt Rushmore in the winter time? “We put it in Rushmore Cave.”
2: A lady from the east coast accosted my wife demanding to see a dangeroo on the Custer State Park wildlife loop. My (then teenaged) wife looked at her and politely said “What the hell are you talking about?” Old lady from the east coast, “The sign said Buffalo and Dangeroo, I want to see a Dangeroo, dammit.” My wife responded “You read the sign wrong lady. It said Buffalo are Dangerous.”
I’ve heard that the guides at the Alamo are getting really tired of people asking “when do we get to see the basement?”
/obscure movie reference from the 80s