 Complete the following phrase:  The Island Park Caldera, in the U.S. states of Idaho and Wyoming, is one of the worlds largest calderas, with approximate dimensions of 80 by 65 km. 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 occurred 2.1 Ma million years ago and produced 2,500 times as much ash as the 