Earth Notes: Closing the Gates of Glen Canyon Dam

Jan 17, 2018

Jan. 21, 1963, marked a watershed in the history of the Southwest. On that Monday, the first gates of Glen Canyon Dam were closed.

Tunnel construction begins: Work on the Glen Canyon Dam began in the fall of 1956 and its first gates were closed Jan. 21, 1963.
Credit U.S. Bureau of Reclamation

Conservationists struck a bargain with the federal government, letting Glen Canyon Dam be built 15 miles above the entrance to the Grand Canyon, instead of the proposed Echo Park Dam in Dinosaur National Monument.

Construction of Glen Canyon Dam began in the fall of 1956. On Oct. 15, President Dwight Eisenhower telegraphed the ceremonial signal for the first dynamite blast in Glen Canyon’s sandstone walls.

Drilling, blasting and mucking began in earnest within the year. The entire flow of the Colorado River was diverted through tunnels bored into solid rock. A canyon-spanning bridge was built, along with an entire new town called Page, Ariz., housing 6,000 people at the project’s peak.  

Bucket after bucket of concrete was poured—5 million cubic yards in all—to form the 710-foot-high gravity-arch dam.

In January 1963, locals were more enthralled with the presence of Charlton Heston, there to film “The Greatest Story Ever Told.” Meanwhile, workers at the dam were chipping away ice so the steel gates in the diversion tunnels would seal properly on the appointed date.

The closing of the gates stilled the Colorado River. Lake Powell began to fill. Seventeen years later the reservoir—second largest in the country—reached full pool, nearing 400 feet deep and reaching 186 miles up the Colorado River.