How Is a River Gorge Formed?
River gorges are found the world over, from the Himalayas to the Alps to the Pacific Northwest. These astounding geological features form over millions of years.Primary FormationRiver gorges are formed by erosion caused by the river that runs through them. Their size correlates to the size of the river, except in instances of stream capture, which occurs when the original river is diverted to another channel.Early EvolutionDuring the formative stages of gorge development, rivers use most of their erosional energy cutting down through rock and soil in a process known as vertical entrenchment. Early river gorges are deep and narrow and are more likely to have waterfalls. West Virginia and Pennsylvania have gorges like this.Later EvolutionLater, the river begins to smooth out the topographic surface of the gorge floor, eliminating waterfalls. The river also begins to concentrate its energy on lateral expansion, increasing the floor width. The Columbia River Gorge in Oregon exemplifies a g
