On May 18, 1980 at 8:32 AM, the top 1300 feet of Mt. St. Helens was blown into the atmosphere reducing it to 8400 feet. The force of the blast was equal to 5,000 H-bombs at was the first lateral blast known to man. It pulverized the north side of the mountain into fine ash that reached an altitude of 63,000 feet, spreading ash eastward across the continent and eventually circling the globe.

Postcards of Mt. St. Helens both before and during the eruption from the Northwest Historical Postcard Collection.