North Cascades Highway SR-20 Avalanche Atlas

The Avalanche Atlas catalogs details of snow avalanche activity along the North Cascades Highway, SR-20, between Newhalem on the west side of the Cascade Mountains and Mazama on the east side. Data contained herein have been collected during summer and winter reconnaissances in 1970 and 1971 under a contract between the Washington State Highway Department and the University of Washington. Compilation of this Atlas completes the first phase of a planned three-year study of avalanche problems and control methods on the highways of the State of Washington. Other work under this first phase is detailed in a separate Summary Report.

Publication Date: 
Tuesday, June 1, 1971
Publication Number: 
WA-RD 8.2
Last modified: 
10/12/2016 - 15:42
Authors: 
E.R. LaChapelle, C.B. Brown, R.J. Evans.
Originator: 
University of Washington. Geophysics Program; University of Washington. Dept. of Engineering.
Number of Pages: 
206
Subject: 
Atlases, Avalanches, Forecasting, Hazards, Highway maintenance, Mountain roads, Mountains, Passes (Mountains), Reconnaissance, Roadside hazards, Snow, Snow and ice control, Snow removal, Terrain evaluation, Topography, Winter maintenance.