Mono Lake is located in beautiful Eastern Sierra; it is one of the oldest lakes in North America. On the way down from the historic Mono Lake you can see both Mammoth Mountain, and Tioga Pass. Department of Water and Power assumed Mono Lake appeared as an isolated lake in the middle of the desert, they didn’t know that in the soon future it would be discovered as a very important place. It also held a rich history in the biological world. The geological history of the Western United States has formed Mono Lake and provided it with the properties it has, those properties have now set it with a precise role in the migration of water birds.
Mono Basin is in one of the most volcanically active places in the world. Stephen Harris’ book Fire Mountains of the West: The Cascade and Mono Lake Volcanoes states “Paoha Island, Negit Island, and Panum Crater are the most recent volcanoes to erupt, which are the furthest north in the basin”. Hot springs and other signs show that this area is still active. Though there have not been any volcanic eruptions in the last six hundred years, there is still evidence of volcanic unrest in the Mono lake.
Geologists' estimate the age of Mono Lake ranges between 1 million and 3 million years. Due to the large amount of mountains surrounding Mono Lake water flows into the lake, but it doesn't flow out, the only way for water to leave Mono Lake is through evaporation. That is why Mono Lake is naturally salty and alkaline. John Harts’ writing in Storm Over Mono: The Mono Lake Battle and the California Water Future informs that “The current lake level is 6382; its surface area is approximately 45,133 acres.” In 1941, the City of Los Angeles, use to divert water from the Mono Basin. That diversion cut the lakes volume in half and doubled its alkalinity and salinity. A very big court fight helped to finally stop the water diversion and allow Mono Lake to once again, naturally flow.