Lake Powell is a reservoir on the Colorado River, between Utah and Arizona. It is a major vacation spot that 2 million people visit every year. It is the second largest man-made reservoir in the United States behind Lake Mead. Due to droughts in the area and high water withdrawals, Lake Powell is currently larger than Mead in terms of volume of water currently held. The flooding of Glen Canyon and the Glen Canyon Dam created Lake Powell. The reservoir is named for Explorer John Wesley Powell a one armed American Civil War veteran who explored the river with wooden boats in 1869.
In 1972, Glen Canyon national recreation area was established. It is managed by the National Park Service. Lake Powell is a water storage facility for the upper basin states of the Colorado River Compact, which include Colorado, Utah, Wyoming, and New Mexico. The compact specifies that the upper basin states are to provide a minimum annual flow of 7,500,000 acre-feet to the lower basin states of Arizona, Nevada, and California.
In the 1940s and early 50s the US Bureau of Reclamation plan to construct a series of Colorado River dams. Glen Canyon Dam was born of a controversial dam site the Bureau selected in Echo Park. A small group of objectors mainly the Sierra Club lead by David Brower, succeeded in relocating the dam site to Glen Canyon. In reality Glen Canyon has a scenic, cultural and wilderness quality often associated with America's national parks. Due to the colorful Navajo Sandstone Canyons and clear streams, abundant wildlife, arches, natural bridges and numerous Native American archaeological sites it would have been a perfect national Park. But it was too late to stop the Bureau from building Glen Canyon Dam. David Brower has always considered the loss of Glen Canyon his life's ultimate disappointment.
Construction on Glen Canyon Dam began with the demolition blast keyed by the push of a button by Pres. Dwight D Eisenhower at his desk in the Oval Office on October 1, 1956. The first blast cleared tunnels and water was diverted through the tunnels so dam construction could begin. Later that year a bridge was completed which allowed trucks to deliver equipment and materials for the dam and created the new town of page, Arizona. 5,000,000 yd.³ of concrete make up Glen Canyon Dam. The Dam is 710 feet high with the surface elevation of the water at full pool being 3700. Construction of the dam cost 155,000 million.18 lives was lost in the process. On September 22, 1966, Glen Canyon Dam was dedicated by Lady Bird Johnson.
At the completion of Glen Canyon Dam, on September 13, 1963 the Colorado River began to backup, and no longer being diverted through the tunnels. The newly flooded Glen Canyon formed Lake Powell. It took 11 years for the lake to fill to 3700 feet and that happened on June 22, 1980. The lake level fluctuates considerably depending on seasonal snow from the Rocky Mountains. The all-time highest water level was on July 14, 1983 during one of the heaviest Colorado River floods in recorded history. In the winter of 2005 the lake reached its lowest level since filling but since then the lake level has slowly rebounded but it has not completely filled since then.
Glen Canyon was carved by differential erosion from the Colorado River over an estimated 5 million years. Within that plateau lie layers of rock from over 300 million years ago and recent volcanic activity. Formations are a result of the ancient inland sea that covered the area. Kayenta sandstone is a blue-black desert varnish that streaks down many walls of the canyon. Navajo sandstone is a result of compressed sand dunes, many of them arches including Rainbow Bridge. The confluences of the Escalante, Dirty Devil and San Juan River's with the Colorado lie within Lake Powell.
The lakes main body stretches up Glen Canyon, but also has filled many side canyons over 90 of them. The lake also stretches up the Escalante River and the San Juan River where they merge into the main Colorado River. This provides access to many natural geographic points of interest including the Anasazi Indian culture.