(CNN NEWSOURCE) – Monday marked the 40th anniversary of the eruption at Mount St. Helens.
The volcano in the Cascade Mountains is in Washington state, nearly 100 miles south of Seattle.
Mount St. Helens was recognized as a volcano in 1835.
There have been at least four significant eruptions over the past five centuries.
The blast on May 18, 1980 killed 57 people and did more than a billion dollars worth of damage.
