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Mono Lake is located in California along the eastern edge of the Sierra Nevada mountain range. It is 760,000 years old and 6380 ft. above sea level (1946m). The water supply comes from underground springs, mainly from runoff from the Sierra Nevadas, but also from other areas.

Mono Lake has no outlet, and the only way water can leave is through evaporation, which causes the minerals in the lake to become concentrated. It is 2 to 3 times saltier than the ocean, and has a very high alkalinity (pH ~ 10).

The unusual formations arising from the lake are called Tufa, which are made from calcium carbonate (limestone or calcite). They are formed when the underwater springs, which are rich in calcium, mix with the lake water that is rich in carbonates. When calcium comes in contact with carbonates, calcium carbonate forms and precipitates around the underground spring. Over decades to centuries, tufa towers grow. They grow exclusively under water and can reach heights of 30 ft. (9.1m). Tufa become visible when the lake level falls.

Mono Lake is a sanctuary, breeding area, and restaurant for almost 100 species of birds; millions arrive and depart between summer and fall. Trillions of brine shrimp and alkali flies provide an unlimited food supply. Some of the birds are residents while others are migratory visitors.

Devil's Postpile National Monument: A nearby volcano erupted 100,000 years ago, spewing basalt lava which cooled and formed these mostly hexagonal vertical columns. About 15,000 years ago, a glacier sheared off the side and top, leaving these 60ft (18m) high columns. The top of the Postpile reveals the hexagonal shapes and parallel groves where rocks carried in the glacial ice scraped across them.