White Sands National Monument

The sands are made of gypsum.   The mineral is dissolved in the mountains to the west by water and then flows down to a dry lake where the water evaporates and leaves crystals.  The crystals are broken into small particles and then the wind blows them to the east to form the White Sands Dunes.  The dunes are about 60 feet high and move across the desert.  The plants stay alive by making their roots longer until the dune passes by.