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?
Yellowstone Caldera
The Yellowstone Caldera is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States, sometimes referred to as the Yellowstone Supervolcano. The caldera and most of the park are located in the northwest corner of Wyoming. The major features of the caldera measure about 34 by 45 miles (55 by 72 km). 
The caldera formed during the last of three supereruptions over the past 2.1 million years: the Huckleberry Ridge eruption 2.1 million years ago (which created the Island Park Caldera and the
National Park Service and the Bureau of Land Management, both under the Department of the Interior. In March 2017, the Idaho Senate voted in favor of petitioning Congress to designate Craters of the Moon a national park.
Geology.
The Snake River Plain is a volcanic province that was created by a series of cataclysmic caldera-forming eruptions which started about 15 million years ago. A migrating hotspot thought to now exist under Yellowstone Caldera in Yellowstone National Park has been implicated. This hot spot was under the Craters of the