At 8:32 Sunday morning, May 18, 1980, Mount St. Helens
erupted.
Shaken by an earthquake measuring 5.1 on the
Richter scale, the north face of this tall symmetrical
mountain collapsed in a massive rock debris avalanche.
Nearly 230 square miles of forest was blown over or left
dead and standing. At the same time a mushroom-shaped
column of ash rose thousands of feet skyward and drifted
downwind, turning day into night as dark, gray ash fell
over eastern Washington and beyond. The eruption lasted 9
hours, but Mount St. Helens and the surrounding landscape
were dramatically changed within moments.
In 1982 the President and Congress created the 110,000-acre
National Volcanic Monument for research, recreation, and
education. Inside the Monument, the environment is left to
respond naturally to the disturbance.