Elk Rock Viewpoint

Note the contrast between replated avalanche surface (west of Elk Rock) and undisturbed avalanche, avalanche levees, lakes, and hummocks below and east of Elk Rock. Note also deposits and effects of the march 19, 1982, lahar, as well as fluvial deposits and downed timber that has not been salvaged. Reworked blast deposit is locally present in this area. Tephra from the May 25, 1980, eruption deposited here has been almost completely removed by erosion.

-- Excerpts from: Doukas, 1990, Road Guide to Volcanic Deposits of Mount St. Helens and Vicinity, Washington: USGS Bulletin 1859, 53p.

View From Parking Area

Here is an excellent view of Mount St. Helens, the debris avalanche, and the spillway draining Coldwater Lake. The crater of Mount St. Helens is 10 miles (16 kilometers) away. The blast deposit was thin here (5 inches (13 centimeters)), and is being eroded further.

-- Excerpts from: Doukas, 1990, Road Guide to Volcanic Deposits of Mount St. Helens and Vicinity, Washington: USGS Bulletin 1859, 53p.

May 18, 1980 Lateral Blast

The near-supersonic lateral blast, loaded with volcanic debris, caused widespread devastation as far as 19 miles from the volcano. ... Trees amounting to more than 4 billion board feet of salable timber were damaged or destroyed, primarily by the lateral blast. ... The force and direction of the blast are strikingly demonstrated by the parallel alignment of toppled large trees, broken off at the base of the trunk as if they were blades of grass mown by a scythe.

-- Excerpt from: Tilling, Topinka, and Swanson, 1990, Eruption of Mount St. Helens: Past, Present, and Future: USGS Special Interest Publication, 56p.