Mono Lake is located just off Highway 395 ... 13 miles east of Yosemite National Park, near the town of Lee Vining, California. Access to 395 from the park is easiest via Highway 120 over the Tioga Pass. A reminder though, Tioga Pass is closed during the winter and, usually, most of the spring.
Mono Lake is unique. For starters, it's old--at least 700,000 years old and one of the oldest continuously existing lakes on the continent. Fed by huge glaciers during the last Ice Age, Mono Lake was 60 times larger than the 66 square miles it covers today.

Mono Lake is naturally salty and alkaline because it has no outlet. The only way water leaves is via evaporation. The Sierra streams that flow into Mono contain only trace amounts of minerals and salts but those minerals and salts stay and their concentrations, over the years, grow.