The U.S. Geological Survey puts on the weeklong camp in conjunction with the Mount St. Helens Institute. The students hiked to places on the mountain to see large mounds called hummocks, and ...

The Mount St. Helens' eruption in Washington on May 18, 1980 is the worst volcanic eruption in U.S. history, killing 57 people and spewing 520 million tons of ash across the U.S.

Though its last eruption was a century ago, California's Lassen Peak is the centerpiece of a volcanic panorama.

On May 18, 1980, Mount St. Helens gave way to a cataclysmic flank collapse, avalanche, and explosion that killed 57 people and displaced many others. The event dramatically reshaped the volcano and… ...

CNN Editorial Research (CNN) — Here’s a look at Mount St. Helens, the most active volcano in the Cascade Mountains in Washington. Facts Mount St. Helens is located in Washington, about 55 ...