The Avalanche Atlas is a two part compilation of snow avalanche activity affecting Washington State highways. Part one catalogs details of snow avalanche activity along Chinook, Cayuse, White and Snoqualmie Passes; part two details of snow avalanche activity along Stevens Pass and Tumwater Canyon. The Atlas includes descriptive details, historical records, photographs, maps and drawings for each avalanche area.
The primary compilation of data for Part 2 of the Cascade Passes Atlas was done by Len Miller during his tenure as a contract avalanche consultant for the Highway Department. This compilation has subsequently been amended and extended through the cooperation of the Department avalanche crew at Stevens Pass under the leadership of Steve Reister. The nomenclature and system of numbering for the avalanche paths adopted in this Atlas is that developed by Miller and Reister. Final compilation, editing and field check were by Edward R. LaChapelle.