The Yellowstone Caldera from an intuitive's perspective

I don't sense this going off "on it's own" during the next 10,000 years beyond the bounds of Yellowstone national park. So, even if it kills a lot of wildlife in the Park and some people it likely won't go beyond the park on it's own.

However, people might do something that cause it to go off through research or terrorists or something like that but if it goes all the way to the Pacific Ocean you can be sure that someone or some government did it and it didn't do it  all by itself.