Lake Mead is the largest reservoir in the United States by water capacity.
It was created by the Hoover Dam on the Colorado River, on the border between Nevada and Arizona. At full capacity, Lake Mead can store roughly 35.2 cubic kilometres of water, though its actual level has often been much lower during prolonged drought and heavy regional demand.
The reservoir began filling in the 1930s after Hoover Dam’s construction. It supplies water to communities and agriculture in several southwestern states and also generates hydroelectric power. Lake Mead lies within the Lake Mead National Recreation Area.
Lake Powell, formed by Glen Canyon Dam farther upstream, is another major Colorado River reservoir and is often compared with Lake Mead. The two are not the same: Lake Mead has the greater maximum storage capacity, while both fluctuate substantially with inflow and use.