Glen Canyon Dam definition of Glen Canyon Dam in the Free Online Encyclopedia.

Glen Canyon Dam, 710 ft (216 m) high, 1,560 ft (475 m) long, NE Ariz., on the Colorado River. The key unit of the U.S. Bureau of Reclamation's Colorado River storage project Colorado River storage project, a multipurpose plan, undertaken by the U.S. Bureau of Reclamation in 1956, to control the flow of the upper Colorado and its tributaries and to aid in the development of the rugged, remote upper Colorado River basin; includes parts of
..... Click the link for more information. , it is one of the world's largest concrete dams (larger in bulk, though not in height, than Hoover Dam Hoover Dam, 726 ft (221 m) high and 1,244 ft (379 m) long, on the Colorado River between Nev. and Ariz.; one of the world's largest dams. Built between 1931 and 1936 by the U.S.
..... Click the link for more information. ). The dam, completed in 1963 and dedicated in 1966 after completion of its power-generation facilities, regulates the flow of the upper Colorado and its tributaries and produces hydroelectricity (since 1964). The dam sharply reduced the seasonal flow of the Colorado downstream, dramatically altering the ecology of the river in the Grand Canyon. Changes in water releases have been experimented with in an attempt to ameliorate the effects of the dam.

Lake Powell, formed by the dam, extends 186 mi (299 km) upstream into S Utah. The lake was named after the American explorer John W. Powell Powell, John Wesley, 1834–1902, American geologist and ethnologist, b. Mt. Morris (now part of New York City). The family moved to Illinois, where Powell joined the Natural History Society, making collections and serving as secretary of the society.
..... Click the link for more information. , who mapped and named the canyon in 1870. This lake is the nucleus of the

Glen Canyon National Recreation Area (see National Parks and Monuments National Parks and Monuments

National Parks
Name Type¹ Location Year authorized Size

acres (hectares)

Description
Acadia NP SE Maine 1919 48,419 (19,603) Mountain and coast scenery.
..... Click the link for more information. , table). Downstream is the Glen Canyon Bridge, 1,271 ft (387 m) long and 700 ft (213 m) high, one of the world's longest and highest steel-arch bridges.