Mount Saint Helens is a prime example of how Earth's topographic form can greatly change even within our lifetimes. The mountain is one of several prominent volcanoes of the Cascade Range that stretches from British Columbia, Canada, southward through Washington, Oregon, and into northern California. Mount Adams (left background) and Mount Hood (right background) are also seen in this view, which was created entirely from elevation data produced by the Shuttle Radar Topography Mission. Prior to 1980, Mount Saint Helens had a shape roughly similar to other Cascade peaks, a tall, bold, irregular conic form that rose to 2950 meters (9677 feet). However, the explosive eruption of May 18, 1980, caused the upper 400 meters (1300 feet) of the mountain to collapse, slide, and spread northward, covering much of the adjacent terrain (lower left), leaving a crater atop the greatly shortened mountain. Subsequent eruptions built a volcanic dome within the crater, and the high rainfall of this area