The Western Cascade of Oregon lie west of the present day High Cascades. They consist of formations similar in nature to those of the High Cascade Range. The High Cascades extend from Canada through Washington and Oregon into northern California. They are currently active but remain dormant in Recent time except for Mt. St. Helens.
Chapter 1 begins with a review of the regional geology. Chapter 2 presents the Western Cascades stratigraphy and volcanics with emphasis on the key components of the region. Chapter 3 discusses the volcanic evolution of the High Cascade Range summarizing Tertiary volcanism and the geologic development of the High Cascade system. Chapter 4 discusses the geomorphic landscapes of the High Cascades beginning with the Columbia River Gorge, reviewing the uplift of the High Cascade Range, glaciology, and volcanoes present along the present day crest. Chapter 5 delves into the details of Quaternary magmatism in the High Cascades discussing the distribution of High Cascade volcanoes including the Washington and Oregon segments extending down to the California state line.
