monolake.html

Mono Lake is a majestic body of water, located 2 hours south of Lake Tahoe on Highway 395, covering about 60 square miles. It is an ancient lake, over 700,000 years old -- one of the oldest lakes in North America. It has no outlet. Throughout its long existence, salts and minerals have washed into the lake from Eastern Sierran streams. Freshwater evaporating from the lake each year has left the salts and minerals behind so that the lake is now about 2 1/2 times as salty and 80 times as alkaline as the ocean. A swim in Mono Lake is a memorable experience. The lake's salty water is denser than ocean water, and provides a delightfully buoyant swim. Old timers claim that a soak in the lake will cure almost anything. Keep the water out of your eyes or any cuts, as it will sting.

The tufa towers are the most obvious geological feature at Mono Lake. These unusual spires and knobs are formed when calcium-bearing freshwater springs well up through alkaline lake water, which is rich in carbonates. The calcium and carbonate combine, precipitating out as limestone. Over many years, a tower forms around the mouth of the spring. This tufa-forming reaction happens only in the lake itself. As the lake level drops, exposing the towers, they cease to grow.