The Cascade Range and the Ring of Fire

Part of Hall of Planet Earth.

The Cascade Range and the Ring of Fire AMNH/R.Mickens

More than 500 volcanoes have erupted during the last millennium, and nearly four-fifths of them constitute the Ring of Fire, a series of volcanic arcs surrounding the Pacific basin. The volcanoes of the High Cascades, with familiar names such as Mount St. Helens, Mount Rainier, Mount Hood, and Medicine Lake, are part of the Ring of Fire and have been volcanically active for the past 12 to 13 million years.

Mount Rainier
Perhaps the most stunning of the Cascade volcanoes, Mount Rainier is a stratovolcano — one consisting of lava flows and ash layers — that has built up over the last million years to an altitude of almost 4,400 meters. Its raised cone supports the largest single glacier system in the “lower 48” states, but its beauty cloaks a potential disaster. During the 20th century, people have settled in the lowland areas surrounding Mount Rainier, and a reawakening of this slumbering giant would melt much of its snow cover, causing surges of mud, ice, and meltwater to race down the slopes.