Where Did the Sand In White Sands, New Mexico Come From and Why Is the Sand So White?

The 275 square mile (715 sq km) White Sands National Monument, in the northern part of New Mexico’s Chihuahuan Desert, is covered with sand made of gypsum crystals, which are usually white.

Sand is defined as sediment created by the mechanical and chemical breakdown of rocks. In the United States, most desert and beach sand is made of quartz crystals.

The source of this gypsum sand is limestone from nearby mountains.

Over time, rain has dissolved the gypsum out of the limestone and carried it down to the Tularosa Basin’s lowest point, the usually dry Lake Lucero lakebed.

From there, winds blow the fine gypsum crystals into the desert. No rivers run out of this basin, so the sand becomes trapped there.

The dramatic dunes at White Sands National Monument, the largest gypsum sand dune field in the world, are constantly changing and shifting position, a result of the strong winds in the area.

Harsh as this environment is, a few plants and animals have adapted to life there.

The four desert regions of the United States, the Great Basin, the Mojave, the Sonoran, and the Chihuahuan, all have slightly different climates.

The Great Basin Desert even gets snow in the winter.