WHITE SANDS NATIONAL MONUMENT

national monument, an expanse of dazzling white gypsum sands in south-central New Mexico, U.S. The area is situated in the Tularosa Basin, between Alamogordo (northeast) and Las Cruces (southwest). Established in 1933, it covers 225 square miles (583 square km) lying between the San Andres Mountains (west) and the Sacramento Mountains (east). The sand constantly drifts into dunes 10 to 60 feet (3 to 18 m) high. In the southwest corner is Lake Lucero, a marsh encrusted with crystals created by the evaporation of gypsum-laden runoff water. The extensive Alkali Flats, to the north of the lake, are similarly created by underground water drawn to the surface. There is little plant life; the animals, mainly mice and lizards, are light-hued, blending with the sand. To the west is the San Andres National Wildlife Refuge. White Sands Missile Range lies to the southwest, and Holloman Air Force Base to the east.