The Salar de Coipasa, located in the Altiplano region of western Bolivia, covers an area of approximately 2,500 square kilometers (960 square miles). The word “salar” describes arid, closed basins in which evaporation of mineral-rich waters leads to the formation of thick, flat salt deposits. Salar de Coipasa is located to the southwest of the saline Lake Poopo and northwest of the largest salt flat in the world, Salar de Uyuni. At Coipasa, a crust composed of halite—common table salt—provides the brilliant white coloration characteristic of the Altiplano salars.
While the environment of Salar de Coipasa is arid, it does receive constant water from the Lauca River flowing in from the north. The Lauca feeds Lake (Lago) Coipasa, which covers the northern end of the basin with shallow water. However, the water flow can drop off sharply during periods of drought.
The waters of Lake Coipasa, and the white salt crust of the salar, also serve to highlight dark river sediments flowing into the basin along the northeastern shore. Dark volcanic rocks contrast sharply with the surrounding salt crust at image left. While the western Andes mountains contain many active volcanoes, the nearby Tata Sabaya volcano (not shown) has not been historically active.