Its ashfall is the source of the Huckleberry Ridge Tuff that is found from southern California to the Mississippi River near St. Louis.

This super-eruption of approximately 2,500 km3 (600 cu mi) occurred 2.1 Ma (million years ago) and produced 2,500 times as much ash as the 1980 eruption of Mount St. Helens.

The plain is a depression, sinking under the weight of the volcanic rocks that formed it, through which the Snake River winds.

These calderas are in an area called Island Park that is known for beautiful forests, large springs, clear streams, waterfalls, lakes, ponds, marshes, wildlife, and fishing.

Snowmobiling, fishing, and Nordic skiing, and wildlife viewing are popular activities in the area.