Mount St. Helens Still Highly Dangerous, 30 Years Later
Washington State mountain ranked second biggest U.S. volcanic threat.
That's because the Washington State volcano poses a triple threat: Mount St. Helens is one of the most active U.S. volcanoes, its eruptions are highly explosive, and it's situated near major metropolitan centers in the Pacific Northwest (see map), said John Ewert of the U.S. Geological Survey's (USGS) Volcano Disaster Assistance Program. (See Mount St. Helens pictures in National Geographic magazine.)
The U.S.—the most volcanically active country after Russia—has 169 volcanoes that the USGS and other agencies regularly monitor. These volcanoes are rated based on eruption frequency and the risks posed
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