Day 2 - White Sands / White Sands Missile Range

General

White Sands National Park lies in southern New Mexico and is completely surrounded by the White Sands Missile Range. It covers the southern 41 per cent of a field of white sand dunes made of gypsum crystals inside the Tularosa Basin, and that dunefield is the largest of its kind on earth: about 4.5 billion short tons of gypsum sand, with dunes as tall as a ten storey building. The park is the reason most visitors come to this stretch of desert, but the military land around it is part of the same story, and the two are impossible to separate once you are standing on the white sand with the San Andres Mountains on one side and a missile range on the other.

The basin that holds the dunes is a graben, a block of the earth’s crust that has dropped between two sets of faults, and it belongs to the Basin and Range Province and to the Chihuahuan Desert. It lies east of the Rio Grande in southern New Mexico and west Texas, mostly in Otero County, and covers an area about a third larger than the state of Connecticut. To the east are the Sacramento Mountains and the Sierra Blanca, to the west the San Andres and Oscura Mountains, and between them the basin runs roughly north to south with a dry floor and no outlet to the sea. Water that does not evaporate or soak away collects in playas, the largest of which is Lake Lucero at the south western end of the dunes.

White Sands Missile Range occupies most of the northern basin and encloses the national park. It was established in 1945 as the White Sands Proving Ground, was renamed the New Mexico Joint Guided Missile Test Range in 1947 and took its present name in 1960, and it is administered by the United States Army Test and Evaluation Command. The range spreads across the San Andres, Oscura and San Augustin mountains, the Tularosa Basin and the Chupadera Mesa, and the cantonment was completed in 1948, with Launch Complex 37 following in 1957. Because the two areas overlap, the park can be closed at short notice when the range is active.

The character of the place comes from the light and the ground. Gypsum sand reflects sunlight instead of absorbing it, so the surface stays cooler than the sand of other deserts, and the white floor throws light upward in a way that makes the horizon hard to judge. Shadows are soft in the middle of the day and long at the edges of it, and the shape of a dune is best read in the first and last hour of sunlight, when the ridges and the slip faces separate clearly. Nights here are unusually dark, which is why the park is also a destination for stargazing.

History

The oldest human evidence in this basin is the most remarkable thing about it. Fossil human footprints in the Tularosa Basin are estimated by the National Park Service at 21,000 to 23,000 years old, and 61 of them had been documented as of November 2021. They are bracketed by layers containing seeds of Ruppia cirrhosa, which give calibrated radiocarbon ages in that range, and one set of tracks appears to show people stalking a giant sloth. That is far older than the present consensus for human arrival in North America, which is placed at 13,000 to 16,000 years ago, and the prints are therefore part of an argument that is still running. Archaic people entered the basin about 4,000 years ago, after the dunes had stabilised.

For most of the nineteenth and early twentieth centuries the dunes were simply in the way of ranching and travel. Spanish settlers tried sheep ranching in the region, and the white sand was valuable enough that commercial exploitation was proposed on a large scale: the deposit is big enough to supply the United States construction industry with drywall for a thousand years. Local residents opposed the idea, and in 1933 President Herbert Hoover declared the gypsum dunes a protected national monument, which prevented mining permanently. It became a national park in 2019.

The missile range began with the end of the Second World War. In 1945 the army established the proving ground in the basin because the land was empty, the weather was stable and the mountains gave natural backstops for long range firing. Operation Paperclip brought more than 1,600 German scientists, engineers and technicians to the United States between 1945 and 1959 for government work, several of them confirmed former members of the Nazi party including the SS and the SA, and many of the earliest American rocket experiments took place here with captured V-2 rockets. The V-2 was a single stage ballistic missile developed in Nazi Germany, more than 3,000 of which were launched against Allied targets from September 1944; after 100 kilometres was adopted as the edge of space, a vertical launch of 20 June 1944 made it retroactively the first artificial object to reach space.

The range is also tied to the beginning of the nuclear age. Trinity, the first detonation of a nuclear weapon, was carried out by the United States Army at 5.29 in the morning on 16 July 1945 as part of the Manhattan Project, in the Jornada del Muerto desert south east of Socorro. The device was an implosion design plutonium bomb of the same type as Fat Man, which was dropped on Nagasaki on 9 August 1945, and the test was planned and directed by Kenneth Bainbridge under the laboratory led by J. Robert Oppenheimer, who chose the code name. About 425 people were present over the weekend of the test. The site was declared a National Historic Landmark district in 1965 and listed on the National Register the following year.

Geology

Gypsum is a soft sulphate mineral, and it is the reason this desert is white. It forms when calcium sulphate in solution crystallises, usually as the mineral selenite, and it is soluble in water, which is why large gypsum sand deserts hardly exist anywhere else on earth: in most deserts the gypsum is carried away before it can accumulate. Here the basin has no outlet, so the mineral has nowhere to go. That single fact, a bowl with no drainage, explains the whole landscape, from the crystals at Lake Lucero to the dunes thirty metres high at the far end of the park.

The sequence that produced the sand runs from the mountains to the dunes. About 12,000 years ago the Tularosa Basin held large lakes, streams, grasslands and ice age mammals. As the climate warmed, rain and snowmelt dissolved gypsum out of the surrounding mountains and carried it into the basin; further warming and drying made the lakes evaporate and left selenite crystals on the floor. Strong winds then broke the crystals into grains and moved them, and the grains have been moving ever since, which is why the dunes shift and why the surface is renewed rather than fixed.

Water still controls the system. Runoff from the San Andres and Sacramento mountains reaches the basin floor, evaporates, and leaves its dissolved load behind, and the playas are the places where the concentration is highest. Lake Lucero is the largest of them, at the south western end of the dunefield, and it is where the crystals can be seen forming today, on the ground that will later become sand. Because the basin is closed, nothing leaves except by evaporation, and the mineral content of the ground slowly rises.

Around the white sand the country is ordinary desert of the Basin and Range type. The basin floor holds sediment washed off the mountains, with dry lakebeds, desert grassland and dark volcanic rocks in places, and the ranges rise sharply from the flats. Basalt flows in the surrounding region produce black rock that contrasts with the white gypsum further south, and erosion continues to fill the basin with mineral rich deposits. The contrast between the black lava, the grey gravel and the white dune field is the clearest picture of geological sorting that a traveller is likely to see in one day’s driving.

Things to See

The dunes themselves are the first destination, and the road into them is the best introduction. The scenic drive runs deep into the gypsum field with viewpoints, picnic areas and trailheads along the way, and after a few miles the road is flanked on both sides by white sand with nothing else in sight. Walking out from any pull off gives the sense of scale that the car hides, and the surface is firm enough to walk on comfortably in the morning, when the sand is cool and the tracks of the previous day have been smoothed away by the wind.

Two walks are worth the time. The Alkali Flat Trail crosses remote sections of the dune field on a route marked by posts, and it offers the widest views of the moving sand; because the posts are the only navigation, it needs to be walked with care and with water. The Interdune Boardwalk is a short paved loop that explains the geology and the ecology of the interdunal flats, including the plants and animals that survive between the dunes. For a longer outing, a ranger led trip to Lake Lucero shows the selenite crystals at their source, which is the one place where the origin of the whole landscape is visible.

The missile range museum is the second half of the day and is reached from the same highway. Its outdoor rocket garden holds historic missiles and aircraft displayed in the desert, with a Nike type army rocket standing against the mountains. Inside there are missiles, an experimental saucer shaped test vehicle, an old optical tracking instrument, a Fat Man bomb casing and a cutaway model of a V-2 beside historic images of V-2 launches on their pads and the people who worked on them. A display case holds Trinitite, the glass formed when the sand at the Trinity site was melted by the blast, described academically in 1948 and usually light green, with a red variety found in one part of the site. Most of the material was bulldozed and buried by the Atomic Energy Commission in 1953, and pieces remain at the site and in museum cases like this one.

The Trinity site itself can be visited only on a few open days a year, because it lies deep inside the range, and the same applies to the McDonald Ranch House where the device was assembled. The surrounding desert is worth looking at on its own account: dry basins, scattered ranges, the Jornada del Muerto where Spanish travellers once crossed, and the long straight roads that connect the towns. For anyone interested in the twentieth century, this is one of the few landscapes where the archaeology of the ice age and the hardware of the space age sit within a few miles of each other.

Timing matters more here than in most parks, for two reasons. The first is the heat: the white sand reflects light upward, so the glare is intense even when the air temperature is moderate, and the middle of the day is uncomfortable in a way that the thermometer does not explain. The second is the wind, which moves loose sand across the surface and fills in the tracks of the previous day; the ridges and the slip faces are cleanest in the early morning. Sledding down the dunes is a local pastime on the steeper slopes, and the park lends itself to it because the sand is smooth and soft.

References

1. Ewing, R. C. & Kocurek, G. (2010). Aeolian dune interactions and dune-field pattern formation: White Sands Dune Field, New Mexico. Sedimentology 57, 1219-1236. doi.org/10.1111/j.1365-3091.2009.01143.x
2. Hunley, J. D. (2008). From Pompton Lakes to White Sands: Other Liquid-Propellant Rocket Developments, 1930-1954. Preludes to U.S. Space-Launch Vehicle Technology. doi.org/10.5744/florida/9780813031774.003.0005
3. Langford, R. P. & others (2016). Transport and mixing of eolian sand from local sources resulting in variations in grain size in a gypsum dune field. Sedimentary Geology 336, 112-125. doi.org/10.1016/j.sedgeo.2015.12.010
4. Lucas, S. G. & others (2002). Mammal footprints from the upper Pleistocene of the Tularosa Basin, Doña Ana County, New Mexico. Geology of White Sands, New Mexico Geological Society Guidebook 53. doi.org/10.56577/ffc-53.285
5. Meinzer, O. E. & Hare, R. F. (1915). Geology and water resources of the Tularosa basin, New Mexico. United States Geological Survey Water Supply Paper 343. doi.org/10.3133/wsp343
6. Morgan, G. S. & Lucas, S. G. (2002). Pleistocene vertebrates from the White Sands Missile Range, southern New Mexico. Geology of White Sands, New Mexico Geological Society Guidebook 53. doi.org/10.56577/ffc-53.267
7. United States Geological Survey (1986). Water resources in basin-fill deposits in the Tularosa Basin, New Mexico. USGS Water-Resources Investigations Report 85-4219. doi.org/10.3133/wri854219
8. Wikipedia contributors (2026). Chihuahuan Desert. en.wikipedia.org/wiki/Chihuahuan_Desert
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11. Wikipedia contributors (2026). Selenite. en.wikipedia.org/wiki/Selenite
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14. Wikipedia contributors (2026). Tularosa Basin. en.wikipedia.org/wiki/Tularosa_Basin
15. Wikipedia contributors (2026). V-2 rocket. en.wikipedia.org/wiki/V-2_rocket
16. Wikipedia contributors (2026). White Sands Missile Range. en.wikipedia.org/wiki/White_Sands_Missile_Range
17. Wikipedia contributors (2026). White Sands National Park. en.wikipedia.org/wiki/White_Sands_National_Park