Why Mono Lake Is Salty Despite Freshwater Inflow

Mono Lake, east of the Sierra Nevada in California, is a terminal (endorheic) lake—it has no outlet to the ocean.

The Salinity Mechanism

1. Freshwater streams flow in, carrying dissolved minerals.
2. Water leaves only by evaporation.
3. Minerals are left behind, accumulating over millennia.

Result

The lake’s salinity is ~100,000 ppm—about 2.5 times saltier than seawater. This extreme chemistry supports unique ecosystems (brine shrimp, alkali flies) but no fish.