Lake Mead (https://www.theepochtimes.com/t-lake-mead) is the largest water reservoir in the United States.
Not only is it just big, but it’s also quite old as well.
It was formed about a hundred years ago, back in the 1930s, due to the construction of the Hoover Dam (https://www.theepochtimes.com/t-hoover-dam): when the Hoover Dam was put up on the Colorado River, Lake Mead was formed behind the dam.