Geology of the Okanogan Highlands 2011 - Stop 6

Continue along Toroda Creek rd for 1.5 miles and turn left onto Nicholson Creek road. The sixth stop provides a view of Corkscrew Mountain.

Be sure to bring your binoculars to get a closer look. The zoom function of a camera may also help.

This photo was taken further down Toroda Creek road, where there is a pull-out large enough for only one or two vehicles.

Corkscrew Mountain Update: Since the field trip, Dr. Dawes conducted some literature research on Corkscrew Mountain. The only geologic publication on Corkscrew Mountain he has found is by Robert C. Pearson of the United States Geological Survey, published in 1988 in the Geological Society of America Abstracts with Programs, (volume 20, number 6). Page 462 provides, "The Geotectobolt-Helical Structure in an Eocene Volcanic Pipe, Northwestern Ferry County, Washington, or, Screwed Up Again." This publication is a partly tongue-in-cheek short article in which Pearson interprets the origin of the steep, twisting layers of volcanic rock on Corkscrew Mountain, which are Eocene in age, about 40-54 million years old. He interprets those corkscrewing rock layers as having formed in the side of a volcanic "pipe," a conduit leading up into a volcanic crater. Dr. Dawes is exploring the possibility of interpreting this geologic feature himself and will keep OHA posted on the results.