At the northern end of the Chihuahuan Desert lies the Tularosa Basin. In the heart of this basin lies one of the world's great natural wonders - the glistening white sands of New Mexico. Dunes of gypsum sand have covered 275 square miles of desert. This is the world's largest gypsum dune field. White Sands National Monument preserves a major portion of the dune field and the plants and animals that have successfully adapted to this hars[h] environment. -From the NPS.
Compared to Great Sand Dune National Park (in set), White Sands' gypsum sand is easy to climb, making trekking across large areas fairly easy, except for that the sun taxes not only from above, but by reflection off the pure, white sands.
White Sands also tastes much different than GSDNP and Death Valley's dunes--those composed of quartz sand.