Clearwater Creek Overlook
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To the north is part of the zone devastated by the May 18, 1980, blast. On the
east wall of Clearwater Creek valley is the east edge of the devastated zone,
about 10 miles from the summit. Most of the fallen or damaged timber has been
salvaged.
-- Excerpts from:
Doukas, 1990,
Road Guide to Volcanic Deposits of Mount St. Helens
and Vicinity, Washington: USGS Bulletin 1859, 53p.
The broad, U-shaped valley of Clearwater Creek was carved by a glacier of Hayden
Creek age (about 140,000 years ago) and possibly by an earilier glacier. On May
18, 1980, the hot blast moved into the upper reaches of the valley, destroying
most of the forest (much of it recently logged). Slope failures, mostly debris
slides, were common during the next few years in this and nearby valleys
affected by the blast. Experimental forest plots were set up to investigate the
causes of the slope failures. One reason was that trees died after the 1980
eruption and their roots stopped providing cohesive strength to the soil.
-- Excerpts from:
Pringle, 1993, Roadside Geology of Mount St. Helens National Volcanic Monument
and Vicinity: Washington Department of Natural Resources, Division of Geology
and Earth Resources Information Circular 88
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