Most canyons are formed by flowing rivers through erosion over long periods of time, and the Columbia River Gorge is a spectacular river canyon cutting through the volcanic rock of the Cascade Mountain Range. Given these facts, what was formed through erosion over long periods of time among the following options: - Columbia River Gorge - a hydraulic system - swamp vegetation - Mississippi River delta - the Moon - Calcium carbonate - the Himalayan mountains - permineralization
The answer to this question is:
Columbia River Gorge