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On May 18, 1980, after two months of tremors, Mount St. Helens erupted spectacularly and profoundly changed a vast area surrounding the volcano. The north slope of the mountain catastrophically failed, forming the largest landslide witnessed in modern times.
1220 SW 3rd Avenue, Suite 1400
Portland, OR 97204 | Get Directions
Phone: (503) 808-2100
Fax: (503) 808-2130