Glen Canyon

Prehistoric cultural periods Studies indicate a chronology for the Lower Glen Canyon prehistory, "from pre-A.D. 1 to the 15th century and recorded history from 1776 to the present". Historic period The recorded history of the canyon begins with the Dominguez–Escalante expedition in 1776, during which Spanish explorers first documented the existence of Glen Canyon. The expedition members crossed the Colorado River in Glen Canyon at the site now known as the Crossing of the Fathers. In the 1830s, trapper Denis Julien may have visited upper Glen Canyon by boat. In 1869 and again in 1871, scientific expeditions led by John Wesley Powell traveled through Glen Canyon en route to the Grand Canyon, resulting in the first formal surveys of the main channel and many of the side canyons. River Mile Zero is at Lee's Ferry, Arizona; the numbers increase as one travels upstream, ending at Mile 169.6 at the confluence with the Dirty Devil River. ==Glen Canyon Dam==

In the 1950s, with the proposal of a dam upstream of the Grand Canyon for water storage and hydroelectric power generation, many environmentalist groups rallied to prevent the inundation of the largely undeveloped canyons in the upper Colorado River watershed. The Sierra Club and many other conservation organizations were instrumental in blocking the proposed Echo Park Dam in Dinosaur National Monument. While Flaming Gorge Dam was built as an alternative to the proposed Echo Park and Split Mountain dams within Dinosaur National Monument, Glen Canyon lacked any protection as either a National Park or Monument. Without that protection, Glen Canyon Dam was authorized and constructed. In 1962, the Sierra Club's David Brower and many others floated the Colorado River through the canyon and realized the tremendous resource it was. The experience transformed Brower's attitude towards environmental preservation, making him more radical and less likely to compromise. His experience has been compared to the experience of John Muir with the Hetch Hetchy Reservoir in California. For Brower, it steeled him for the 1960s battle over the proposed Marble Canyon Dam in the Grand Canyon. American writer Edward Abbey also documented his experience exploring Glen Canyon from the Colorado River prior to the completion of Glen Canyon Dam in his 1968 memoir Desert Solitaire, in the chapter titled "Down the River". ==See also==