Lake Mead is a man-made lake that lies on the Colorado River, about 24 mi from the Las Vegas Strip, southeast of the city of Las Vegas, Nevada, in the states of Nevada and Arizona. It is the largest reservoir in the United States in terms of water capacity. Formed by the Hoover Dam on September 30, 1935, the reservoir serves water to the states of Arizona, California, and Nevada, as well as some of Mexico, providing sustenance to nearly 20 million people and large areas of farmland.At maximum capacity, Lake Mead is 112 miles long, 532 feet at its greatest depth, has a surface elevation of 1,221.4 feet above sea level and 247 square miles of surface area, and contains 26.12 million acre feet of water.
The lake has remained below full capacity since 1983 due to drought and increased water demand. As of July 2019, Lake Mead was at approximately 40% of full capacity with 10.4 million acre feet of held water. It has been smaller than Lake Powell since 2013.