40,000 years ago the salt flats were a part of Lago Minchin, a giant prehistoric lake. When this lake dried, it left behind two modern lakes, Lagos Poopö & Uru Uru, and the two major salt deserts, Coipasa and the larger Uyuni.
Salar de Uyuni is estimated to contain 10 billion tons of salt of which less than 25,000 tons is extracted annually. Every November Salar de Uyuni is also the breeding grounds for three breeds of South American flamingos - Chilean, James and Andean. Salar de Uyuni is also a significant tourist destination in western Bolivia.