Cordilleran Section of the Geological Society of America

One of six volumes generated by each GSA section for the Decade of North American Geology (DNAG) project, this Centennial Field Guide contains descriptions of 100 sites or site clusters representing outstanding geologic locations in Alaska, southern Arizona, California, Hawaii, Nevada, Oregon, Washington, and British Columbia.
Columbia River Basalt Group, Joseph and Grande Ronde canyons, Washington
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Published:January 01, 1987
Abstract
The Grande Ronde-Joseph Canyon area is located in southeast Washington near the common boundaries of Washington, Oregon, and Idaho (Fig.1). The locality lies within the canyon country which forms the southeast part ofthe Columbia Plateau Province near the eastern termination of the Blue Mountains and the southern boundary of the Lewiston Basin.
The site can be reached by following Washington SR 129 south from Clarkston to Asotin, Washington, and then by following the Snake River road (lst street in Asotin) south from Asotin for 25 mi (40 km) to the confluence of the Snake and Grande Ronde rivers. The...