Yellowstone sits on top of one of the world 's largest volcanoes . The volcano is about as old and massive as our own planet, but it has a much smaller volume than Earth does. Maintenance crews quickly repaired the road , and it was reopened to visitors Saturday . No volcanic eruption is expected for 1,000 years or more .
Yellowstone sits on top of one of the world 's largest volcanoes . The volcano is about as old and massive as our own planet, but it has a much smaller volume than Earth does. No volcanic eruption is expected for 1,000 years or more .