Below the Wasatch Range’s Storm Mountain

November 24, 2022


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Photographer: Ray Boren

Summary Author: Ray Boren 

Geologic forces spanning millions of years — from estuarine deposits and metamorphic pressures to mountain building and never-ending erosion — are exposed in beautiful Big Cottonwood Canyon, a cleft in the Wasatch Range southeast of Salt Lake City, Utah. Accessible examples of these phenomena are found alongside a graceful curve in the canyon highway below ominously named Storm Mountain. Here, tinted in shades of oxidized red and darker black, are layered Big Cottonwood Formation rocks, as illustrated in the first photo, taken on October 19, 2022. 

The eye-catching outcrops at Storm Mountain include quartzite, a dense, quartz-rich sandstone, and argillite, a clay-rich mudstone. The layers were originally laid down over 720 million years ago, during the Neoproterozoic. They were subsequently uplifted, folded and steeply tilted beginning about 75 million years ago, creating this rugged landscape. The quartzites were originally deposited in rivers and tidal channels, while the argillite comes from calmer deposits — both evidence of an ancient, seaside estuary that preceded the mountains themselves.

A second photograph, taken the same day from below an overhang in the rocks and above the curving highway, partly shows Storm Mountain’s steep, craggy face, to the left. The peak rises some 2,100 feet (700 meters) above the canyon, topping out at 9,528 feet (2,904 meters) above sea level. The perspective also hints at the season under way: The leaves of stream-side mountain maples, cottonwoods, oaks and other deciduous trees and bushes have turned autumnal shades of red and yellow, for their production of chlorophyll has ceased with the arrival of fall’s cooler temperatures and shorter days. 


Big Cottonwood Canyon, Utah Coordinates: 40.6373 -111.6330

Related Links:

Autumn Colors in Utah's Wasatch Range

Wasatch Mountains and Salt Lake Valley