45 years after blast, Mount St. Helens’ sediment still causing costly problems
Nearly 45 years after Mount St. Helens' eruption sent almost 90 billion cubic feet of debris into the upper Toutle Valley, ...
The Columbian11d
45 years after blast, Mount St. Helens’ sediment still causing costly problems
while Castle Rock and Longview have changed their systems in light of the blast. The U.S. Army Corps of Engineers continues to monitor sediment levels. Mountain runoff carries ashen remains of ...