Geologic Publications for Mount Rainier

Mount Wow rock fall, preliminary findings

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Author(s): Scott R. Beason

Category: PUBLICATION
Document Type: Unpublished Document
Publisher: Mount Rainier National Park
Published Year: 2014
Volume:
Number:
Pages: 7
DOI Identifier:
ISBN Identifier:
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Abstract:
On Thursday, May 15, 2014 at about 10:30 AM, approximately 8,500 cubic feet of Oligocene-age (~30 ma) Ohanapecosh Formation andesite slid off the east face of Mount Wow at about the 4,000-foot level. The rock fall traveled approximately one-quarter-mile down a steep talus and scree slope, and deposited large boulders on the West Side Road parking area at the 2,800-foot level. An NPS owl crew further up the West Side Road heard the rock fall, allowing the timing of the event to be determined. A visitor’s vehicle was totaled by a large rock and the parking area sustained impact crater damage from the boulders. No eyewitnesses directly observed the event itself and there were no injuries sustained. The largest of the craters in the road/parking area is approximately 8 feet wide by 3 feet deep. Numerous boulders were deposited on the scree field between the source and deposition areas, including a boulder that is roughly 30 feet wide by 20 feet long by 5 feet high. About 45 boulders with a diameter greater than 1 foot reached the parking area, with an estimated combined volume of 4,345 cubic feet. It is estimated that at least this much additional material stopped short of the parking area and is deposited on the scree field above the road. Therefore, we estimate the size of the rock fall to be approximately 8,500 cubic feet (315 cubic yards; or 31.5 dump trucks worth of material).

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Suggested Citations:
In Text Citation:
Beason (2014) or (Beason, 2014)

References Citation:
Beason, S.R., 2014, Mount Wow rock fall, preliminary findings: Unpublished Document, Mount Rainier National Park, 7 p..