Mono Lake is a lake in Mono County, California, formed at least 760,000 years ago as a terminal lake in a basin that has no outlet to the ocean. Because it lacks an outlet, dissolved salts make the lake very alkaline and salty. Mono Lake formed because it lies in the Mono Basin, an endorheic basin that has no outlet to the ocean. Dissolved salts in the runoff thus remain in the lake and raise the water's pH levels and salt concentration. The Mono Lake tributaries include Lee Vining Creek and Rush Creek.
