A photo of Banks Lake
By Geology and Ecology of National Parks
June 2011 (approx.)
Detailed Description
Outcrops along Banks Lake (reservoir) consist of granitic rock (granite, granodiorite, and diorite). These rocky outcrops near Steamboat Rock State Park demonstrate that a rugged, possibly mountainous landscape existed in the region before the massive basalt flows spread across the region forming the Columbia River Plateau.
Sources/Usage
A photo of Banks Lake