Glen Canyon Dam A dam in Glen Canyon was studied as early as 1924, but these plans were initially dropped in favor of the Hoover Dam (completed in 1936) which was located in the Black Canyon. By the 1950s, due to rapid population growth in the seven U.S. and two Mexican states comprising the Colorado River Basin, the Bureau of Reclamation deemed the construction of additional reservoirs necessary. However, the USBR faced opposition when it proposed the Echo Park Dam in Utah's Dinosaur National Monument, which the nascent environmental movement saw as a legal threat to the status of protected lands. After a
Colorado River basin. Phoenix in Arizona and Las Vegas in Nevada are the largest metropolitan areas in the watershed. Population densities are also high along the lower Colorado River below Davis Dam, which includes Bullhead City, Lake Havasu City, and Yuma. Other significant population centers in the basin include Tucson, Arizona; St. George, Utah; and Grand Junction, Colorado. Colorado River basin states are among the fastest-growing in the U.S.; the population of Nevada alone increased by about 66 percent between 1990 and 2000 as Arizona grew by some 40 percent. The Colorado River basin shares drainage boundaries with many other major watersheds