(CNN NEWSOURCE) — Monday marks 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.
(Information from CNN Newsource)