May 18th, 1980, Mount St. Helens finally came through on it’s
threats and erupted spectacularly, throwing ash 16,000 feet into
the air. 23 square miles of material were moved, most of it in
the largest landslide in recorded history buried the North Fork
of the Toutle River at least 150 feet, and in some areas up to
600 feet. 230 square miles of old growth forest were devastated.
While no lava spewed from the Mountain, a Pyroclastic flow of
superheated materials covered six square miles of land. Ash was
heavily deposited over eastern Washington, Idaho and Montana,
South Dakota and Nebraska. Places such as Los Angeles and
Virginia received wind born ash. 200 houses, 15 miles of road,
several bridges, and a Boy Scout Camp were destroyed. 57 seven
people were killed in the blast. Sediments from the rivers
flowing into the Columbia River closed the river for six days
before the US Army Corps of Engineers could clear the channel
enough for ships to come in at high tide. Even now, the sediment
and ash still occasion