The Island Park Caldera is one of the world's largest calderas at 18 miles (29 km) long and 23 miles (37 km) wide, in eastern Idaho just to the southwest of the Yellowstone Caldera.
The Island Park Caldera is one of the world's largest calderas at 18 miles (29 km) long. This is in eastern Idaho. The Island Park Caldera is 23 miles (37 km) wide just to the southwest of the Yellowstone Caldera. This is in eastern Idaho.