canyon

Cross section of a canyon. Canyons are formed in dry regions where rivers maintain a constant flow of water over long periods of time. The Grand Canyon, for example, was first cut around 26 million years ago, in Miocene times.

Deep, narrow valley or gorge running through mountains. Canyons are formed by stream down-cutting, usually in arid areas, where the rate of down-cutting is greater than the rate of weathering, and where the stream or river receives water from outside the area.

There are many canyons in the western USA and in Mexico, for example the Grand Canyon of the Colorado River in Arizona, the canyon in Yellowstone National Park, and the Black Canyon in Colorado.

Canyon

City in the panhandle of northwestern Texas, USA, on the Prairie Dog Town Fork of the Red River, 26 km/16 mi south-southwest of Amarillo; seat of Randall County; population (1990) 11,400. Once a ranch headquarters, the city is now a trade centre for a farming and cattle raising area. Its largest employer is West Texas State University (1909), home to the Panhandle-Plains Historical Museum.

The last great Indian battle in Texas, fought here in 1874, was a cavalry victory over an encampment of Comanches. Palo Duro Canyon State Park is just to the east, and Buffalo Lake National Wildlife Refuge is 19 km/12 mi to the southwest.