For over a century, tens of millions of visitors have marveled at the natural beauty of Yellowstone National Park. But, beneath all this beauty lurks a beast. Yellowstone sits directly above one of the largest volcanic systems on Earth. For the past two million years, this supervolcano has erupted roughly every 600,000 years. The last major eruption occurred 640,000 years ago. So, is it overdue for another eruption? There have been disturbing signals... Supervolcano: Yellowstone's Fury examines...