brown canyon walls covered with green shrubs with view of ocean in background
San Nicolas Island Canyon. ©Steve Schwartz.

A canyon is formed when the flow of a stream or river causes the land around it to erode, as it cuts its way deeper and deeper into the rocks. Canyons are sometimes also called ravines or gorges. The Grand Canyon in Arizona was formed by the flow of the Colorado River.

Last updated: November 9, 2018