When Mount St. Helens erupted on May 18, 1980, the landscape changed in an instant—the geologic version of an instant, anyway. It was the deadliest eruption the United States had ever seen, leveling ...

The most destructive volcanic eruption in United States history happened less than half a century ago in Washington state. On May 18, 1980, the north side of Mount St. Helens, in southwestern ...

Mount Rainier’s cousin Mount St. Helens, farther south in the Cascade Range, triggered a devastating lahar when it erupted four decades ago, although it did not reach any densely populated areas.

(CNN) — The snowcapped peak of Mount Rainier, which towers 4.3 kilometers (2.7 miles) above sea level in Washington state, has not produced a significant volcanic eruption in the past 1,000 years. Yet ...