A Miocene Forest Assemblage in the Columbia River Basalts of Washington State, USA

This report describes a fossil locality in Washington State in which fossil trees are preserved standing upright in a Miocene basalt flow. Topics include the Columbia River Flood Basalts (one of which inundated the trees), a description of the fossil site, the ages of the basalt and the underlying clay, analyses of the fossil wood to determine tree species, and a discussion of the depositional environment in which the trees are preserved. Educational levels: Undergraduate upper division, High school, Undergraduate lower division