Skip to main content
U.S. flag

An official website of the United States government

Scientist investigates bedrock canyon, North Fork Fortymile River, AK

Detailed Description

A scientist investigates a bedrock canyon cut by the North Fork Fortymile River in response to human mining activity in 1900. The smooth grooves on the rock in the lower right corner were formed by river erosion in the last century. The study of this canyon provides rare insight on the fundamental yet seldom seen process of bedrock gorge formation and highlights long-lived impacts of brief human activity on the landscape. The study is available in Geology at:


Public Domain.