From a distance White Sands looks like a snowfield in the desert. Up close the "snow" is warm, soft gypsum sand, piled into dunes across 275 square miles (710 km²) of New Mexico's Tularosa Basin. It is the largest gypsum dunefield on Earth, and since December 2019 the heart of it has been protected as White Sands National Park.

Soaptree yucca growing among rippled white gypsum dunes at White Sands

How the gypsum dunes formed

The story begins in the Permian Period, when shallow seas left thick layers of gypsum. Later uplift raised that gypsum into the mountains that ring the basin. Rain dissolves it and carries it down, and because the Tularosa Basin has no outlet to the sea, the mineral has nowhere else to go.

During the last ice age a large lake, Lake Otero, covered much of the basin. When it dried out it left the Alkali Flat. Today the process continues at Lake Lucero, a dry lakebed in the park's southwest. Floods fill it from time to time, and as the water evaporates it leaves selenite crystals. Wind and weather break the crystals into sand-sized grains, and the prevailing wind pushes them out into the dunefield.

Gypsum rarely survives as sand, because it dissolves easily in water. Here the dry climate and the closed basin let it build up.

Rippled gypsum dune under a blue sky with mountains on the horizon, White Sands
White Sands dunes at sunrise with clouds over the mountains – photograph by Edward Webster
Photo: Edward Webster.

A landscape in motion

The dunes are always moving slowly downwind. On the western side, closest to the source, they travel fastest and carry little vegetation. Toward the east they slow down, and plants such as yucca, grasses and shrubs take hold, binding the sand with their roots.

Look at the photographs for the signs: ripples on the windward slopes, sharp crests and the steep slip faces where sand avalanches down the leeward side. A lone soaptree yucca rising out of the sand is one of the classic White Sands images.

Life has adapted to the white background too. The bleached earless lizard and the little white whiptail are pale versions of species found elsewhere, and the Apache pocket mouse and the White Sands woodrat live only here. At least 45 species are found nowhere else, 40 of them moths.

Smooth curving white dunes and a ridged patch of sand at White Sands
Sharp dune crest against a deep blue sky – photograph by John E. Hunter
Photo: John E. Hunter

From national monument to national park

President Herbert Hoover proclaimed White Sands National Monument on 18 January 1933. It became a national park on 20 December 2019, when the change was signed into law. The park covers about 145,000 acres and protects around 42% of the dunefield. Most of the rest lies to the north inside White Sands Missile Range, the military testing area where the world's first nuclear test, Trinity, took place in 1945.

The military neighbours still shape a visit. During missile tests the park and US Highway 70 can close for safety, usually for up to three hours, with notice normally given about two weeks ahead. Holloman Air Force Base lies just to the east, and military aircraft are a common sight over the dunes.

Yucca and shrubs on the dunes under evening clouds – photograph by Chris Sanner
Photo: Chris Sanner

Visiting White Sands: getting there and what to do

The park entrance and visitor centre sit on US 70 about 15 miles (24 km) from Alamogordo and 52 miles (84 km) from Las Cruces. The nearest large airport is El Paso, around 85 miles (137 km) away. The National Park Service planning information covers hours, fees and current notices.

Dunes Drive runs 8 miles (13 km) from the visitor centre into the heart of the dunefield. Five marked trails add up to about 9 miles (14 km), from short, easy walks to longer routes across the dunes. Trails are marked with posts. If you cannot see the next marker, turn back, because footprints disappear quickly in moving sand. Sledding on the dune slopes is a favourite activity in every season.

Rangers lead full-moon hikes from April to October and monthly tours to Lake Lucero from November to April. March and July are the busiest months. Spring and autumn bring the most comfortable temperatures.

Check the NPS current-conditions page before you go. In September 2026 it listed a safety corridor between miles 3 and 5.5 of Dunes Drive where stopping and parking are not allowed, and backcountry camping was closed. Carry plenty of water: the NPS hiking guidance advises against starting a hike when it is 85°F (30°C) or hotter.

Long ripple lines leading across a dune in low light – photograph by Michael Keel
Photo: Michael Keel
White dune silhouetted against an orange sunset sky – photograph by Tom DiMatteo
Photo: Tom DiMatteo
Wavy ripple patterns on white sand under small clouds at White Sands

More pale landscapes to explore

White Sands pairs well with other places where one mineral colours the whole view. Bolivia's salt flat is the obvious companion: read our Salar de Uyuni guide. If dune walks have you thinking about the outdoors more generally, our hiking article looks at what time on the trail does for the mind.

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