White Sands National Monument

 

Location: Otero Country, NM Map

Area: 581 km²

Info: (575) 679- 2599

Open: 8am- 7pm daily (5pm in winter months)

Closed: Dec. 25

Official site

 

Description of White Sands National Monument

White Sands National Park is a national park-type preserve about 16 miles southwest of Alamogordo, New Mexico, at the northern end of the Chihuahuan Desert. In a wide valley - the Tularosa Basin - it includes the southern part of a 712 km² large gypsum field on which huge dunes have formed.

 

Tularosa Basin

The gypsum that makes up the White Sands formed the bottom of a shallow sea that covered this region 250 million years ago. Eventually, sedimentary rock enriched with marine deposits emerged, which was thrown up into a gigantic dome around 70 million years ago when the Rocky Mountains formed. Around ten million years ago, the center of this dome began to collapse, forming the Tularosa Basin. The remaining edges of the sagging dome formation today form the San Andres Mountains and Sacramento Mountains.

 

Genesis

White Sands
Gypsum (calcium sulfate dihydrate) is a mineral found high up in the San Andres and Sacramento Mountains. Due to the uplift of the mountains, it was loosened from the rocks over time by snow and rain. It then entered the Tularosa Basin and was successively deposited there as sediment. Rivers would normally carry this to the sea, but since there is no outflow in the Tularosa Basin, the gypsum and other dissolved sediments are trapped within the valley. After the water evaporated from the sediment, the gypsum crystallized. The crystals in turn shattered into grains, which were piled up by the wind into huge white dusty dunes.

One of the valley's lowest points is a large dry lake that periodically fills with water: Lake Lucero. As soon as its water evaporates again, dissolved gypsum collects on the surface.

During the last Ice Age there was even more gypsum deposits as a large lake - Lake Otero - covered most of the valley. It dried up and left a large alkaline plain.

 

Sand dunes

During periods of wet weather, when the water slowly evaporates, the gypsum deposits at the bottom of the dry lake in a crystalline form known as selenite. Along the shores of Lake Lucero and the Alkali Plains, selenite crystals, some up to a meter long, cover the ground and form layers. The forces of nature, cold and heat, wet and dry, eventually break the crystals into small sand particles light enough to be blown away by the wind.

Strong winds blow across the dry lake, picking up gypsum particles and carrying them with them. As the sand grains pile up into dunes, they bounce against the gently rolling, windward side of the dune, producing small ripples on its surface. On the steep crest of the dune, the sand builds up until gravity causes it to slide; this causes the dune to move forward.

There are four different types of dunes in White Sands:
Domed Dunes: The first dunes to form upwind of Lake Lucero are low sand hills that move up to ten meters annually.
Barkand Dunes: Crescent-shaped dunes form in areas with strong winds that bring limited new sand with them.
Diagonal Dunes: In areas that are adequately supplied with sand, crescent-shaped dunes join together to form long mountain ranges of sand.
Parabolic Dunes: Along the edges of the dune field, plants anchor the foothills of the crescent-shaped dunes to each other, inverting their shape.

 

Flora and fauna

Even plants and animals well equipped for life in the desert have trouble surviving in the changing world of the dunes. A small number of plants have changed and adapted and are thus able to avoid being constantly buried under sand. The Soap Tree Yucca lengthens its stem so its leaves are always above the sand, growing up to 30cm per year. Other plants hold part of the dune with their roots and can continue to grow on the sand base anchored in this way while the dune moves.

As in other deserts, most of the animals that live here stay in their burrows underground during the heat of the day and only emerge at night. In the morning you can find traces of rodents, rabbits, foxes, coyotes, porcupine and other nocturnal animals in the sand. Lizards, beetles and birds are diurnal and can be seen in the plant areas. A few animal species, such as a pocket mouse, two species of lizards, and various insects, have evolved a white camouflage color that protects them from their predators.

 

National park

Starting at the visitor center at the entrance to the park, Dunes Drive leads twelve kilometers into the middle of the dunes, from where they can be explored on foot via four marked trails. In summer, the rangers also offer guided tours. However, about once or twice a week, the park is closed for safety reasons when missile tests are being conducted at the White Sands Missile Range surrounding the park.

The sanctuary was established as a national monument in 1933. In 2008, the National Monument was included in the tentative list for nomination for UNESCO World Heritage. In December 2019 it was turned into a national park.

 

Archeology

In 2009, Homo sapiens footprints were discovered in a dried-up lake bed. The traces could be indirectly dated to an age of 23,000 years via seeds of the aquatic plant Ruppia cirrhosa in the imprints. That would be near the peak of the last glacial period, almost 10,000 years earlier than previous confirmed dates of humans in North America. In 2022, the dating was questioned because comparative samples indicate that old 14C was deposited in the plant parts with the water at the site. A falsification of the dates by about 7000-10,000 years to an estimated 13,350 cal yr BP due to this effect cannot be ruled out.