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
Transportation in Arizona large-scale reconstruction and expansion of I-10 was supported and completed in mid-2009. Yuma is served by I-8, while Casa Grande served by I-8 and I-10; Flagstaff is served by I-17 and I-40. US 95 parallels the Colorado River, from Las Vegas to the Mexico–United States border near Yuma. Historic US 66, a major route for Midwestern emigrants prior to the advent of the interstate highway system, traversed the northern part of the state, passing through Flagstaff and Kingman. US 66 in Arizona closely followed the route of what is now I-40 except for an stretch between Seligman and Kingman now