Course of the Colorado River Lake Mead, formed by the -high Hoover Dam about southeast of Las Vegas, Nevada, is the largest reservoir in the United States with a full capacity of and a water surface of nearly . However, the lake has not been full for many years due to a combination of drought and increased water usage by Colorado River Basin states. Situated in the Lake Mead National Recreation Area, Lake Mead is a popular recreation site – visited by almost 8 million people a year – and a critical source of water for the Las Vegas metropolitan area, Central Arizona and Southern
History of the Grand Canyon area geologic observations of the canyon and surrounding area in 1856. Jacob Hamblin (a Mormon missionary) was sent by Brigham Young in the 1850s to locate easy river crossing sites in the canyon. Building good relations with local Native Americans and white settlers, he discovered Lee's Ferry in 1858 and Pierce Ferry (later operated by, and named for, Harrison Pierce)—the only two sites suitable for ferry operation. In 1857 Edward Fitzgerald Beale led an expedition to survey a wagon road from Fort Defiance, Arizona to the Colorado River. On September 19 near present-day National Canyon they came upon what May Humphreys