White Sands National Monument is in the heart of the Tularosa Basin, New Mexico. Here, great wave-like dunes of gypsum sand have engulfed 275 square miles of desert and created the world's largest gypsum dune field.

The National Monument preserves a major portion of this unique dune field, along with the plants and animals that have successfully adapted to this constantly changing environment.

The gypsum that makes up the white sands starts out as clear, translucent sand grains. As the wind bounces the sand grains along the ground, they collide and scratch each other. The scratches change the way light reflects off the grains, making the sand appear white. The white sands dune field is an active dune field. The dunes move from west to east as much as thirty feet per year.

Because there is virtually no fresh water within the white sands dune field, animals that live in the dunes must get almost all their water solely from the food they eat. Desert animals have evolved many ways of conserving moisture. The kangaroo rat eats only dry seeds and never drinks water.