Yellowstone National Park is a great place to visit if you're ever in Wyoming, Montana, or Idaho!
I have been to Yellowstone a few times.  Very interesting geology there.  Have you ever heard of the super-caldera there?
Are you talking about the Yellowstone Caldera? The volcanic caldera and supervolcano in the parl?
Yes, that is it!  Do you know anything about it?
Well, like the rest of the park, the caldera is located in the northwest corner of Wyoming!
Any idea on how often it erupts, or the last time it erupted?
Well, the last time it erupted was 2.1 million years ago, so I don't know if I would expect to see it go off again 
Well, that is comforting then.  When was the park founded?