Sixty people were dead or missing, including one USGS volcanologist, David Johnston, who was monitoring the mountain from nearby. Before the eruption, Mount St. Helens towered about a mile above its base, but on 18 May 1980 its top slid away in an avalanche of rock and other debris. Look at the zoomed-in images . Forested areas appear red. Ash, mudslides, and mud-laden rivers show as grayish blue.
Water looks black.
Ice and snow are white. 3 Coldwater Creek and Castle Creek, which are tributaries of the Toutle, were blocked by this debris, forming Coldwater Lake and Castle Lake. Spirit Lake, northeast of the peak, also flowed into the river. The avalanche raised its level 60 m. The 1988 and 1992 images show gradual vegetation regrowth, as light red and pink, in the devastated area.