The giant supervolcano that lies under Yellowstone National Park is cooling off in the west but staying hot in the northeast.
Large explosive eruptions occur in Yellowstone around once every 700,000 years, according to the U.S. Geological Survey.
(National Park Service) The caldera-forming eruptions at Yellowstone ... beneath the ground – down to the boundary of ...
Yellowstone’s popularity overshadowed a relatively unknown Oklahoma national park. With so much competition, the park no longer exists.