Nation A supervolcano in Utah? It’s 30 times larger than Yellowstone’s February 10, 2020Lexi Peery, St. George Spectrum & Daily NewsComments Off on A supervolcano in Utah? It’s 30 times larger than Yellowstone’s A supervolcano discovered in southern Utah erupted 30 million years ago in an explosion 5,000 times larger than the Mount St. Helens disaster.