Mono Lake Tufa State Natural Reserve

Situated on the eastern slope of the Sierra Nevada near Lee Vining, California, the Mono Lake Tufa State Natural Reserve protects a surreal, ancient inland sea and the strange geological towers that rise from its surface. Mono Lake is at least 760,000 years old, making it one of the oldest lakes in North America. Lacking an outlet to the ocean, water leaves the basin solely through evaporation, which leaves behind high concentrations of salts and minerals that give the water a slick, alkaline feel and a chemistry entirely hostile to fish.

The defining visual feature of the reserve is its tufa towers—knobby, calcium-carbonate spires that pierce the water and dot the receding shoreline. These formations are born from an invisible architecture: freshwater springs rich in calcium bubble up from the lakebed, meeting water heavily charged with carbonate. The resulting chemical reaction causes limestone to precipitate out around the underwater springs. Over centuries, these mineral deposits accumulate into towering columns.

For most of the twentieth century, the lake's existence was threatened. In 1941, the Los Angeles Department of Water and Power began diverting the streams that fed Mono Lake to supply water for Southern California. By 1982, the lake's volume had been halved, its surface area reduced by a third, and its salinity doubled. This drastic drop exposed the tufa towers, which had previously been hidden beneath the water's surface, turning the lake into a graveyard of pale, ghostly spires and threatening the ecosystem of brine shrimp and alkali flies that millions of migratory birds rely on.

A prolonged legal battle, championed by local activists and conservationists, eventually led to a landmark 1994 State Water Resources Control Board decision that protected the streams and mandated the lake be allowed to partially refill. Today, visitors encounter a starkly beautiful landscape where otherworldly limestone towers stand as monuments to a hard-fought environmental victory, framed by the dramatic backdrop of snow-capped mountains.