White Sands National Park is an American national park located in the state of New Mexico and completely surrounded by the White Sands Missile Range. The park covers 145,762 acres (227.8 sq mi; 589.9 km²) in the Tularosa Basin, including the southern 41% of a 275 sq mi (710 km²) field of white sand dunes composed of gypsum crystals. This gypsum dune field is the largest of its kind on Earth, with a depth of about 30 feet (9.1 m), dunes as tall as 60 feet (18 m), and about 4.5 billion short tons (4.1 billion metric tons) of gypsum sand.

Approximately 12,000 years ago, the land within the Tularosa Basin featured large lakes, streams, grasslands, and Ice Age mammals. As the climate warmed, rain and snowmelt dissolved gypsum from the surrounding mountains and carried it into the basin. Further warming and drying caused the lakes to evaporate and form selenite crystals. Strong winds then broke up crystals and transported them eastward. A similar process continues to produce gypsum sand today.

Thousands of animal species inhabit the park, a large portion of which are invertebrates. Several animal species feature a white or off-white coloration. At least 45 species are endemic, living only in this park, with 40 of them being moth species. The Tularosa Basin has also seen a number of human inhabitants, from Paleo-Indians 12,000 years ago to modern farmers, ranchers, and miners.

The potentially oldest known human footprints in North America were found at White Sands by researchers who identified approximately 60 fossilized footprints buried in layers of gypsum soil on a large playa in the Tularosa Basin. Multiple human footprints are stratigraphically constrained and bracketed by layers containing seeds of Ruppia cirrhosa that yield calibrated radiocarbon ages between 23 and 21,000 years ago, according to the U.S. Geological Survey. The present consensus for human arrival into North America is placed at 13-16,000 years ago. However, these estimates have been questioned by other authors, who suggest that the dating could potentially be erroneous, due to the fact that Ruppia cirrhosa intakes carbon from the water in which it grows rather than the air, which may introduce systematic errors making the seeds seem older than they actually are. However, the date was later supported by radiocarbon dating of pollen and optically stimulated luminescence dating of quartz grains within the footprint layers. Other tracks are known for extinct megafauna, including ground sloths (likely either Nothrotheriops or Paramylodon) and Columbian mammoths, which appear to be contemporaneous to human footprints.