Sakt Flats

The salt flats in Badwater Basin cover nearly 200 square miles, among the largest protected salt flats in the world.
Three basic things are needed for salt flats to form:

* source of salts, usually from a large drainage system
* enclosed basin that doesn't drain to the sea and wash away the salts
* arid climate where evaporation exceeds precipitation, leaving behind just the salts and fine silt

Source: National Park Service