Tired of snow? Come slide on the dunes at White Sands

In the Tularosa Basin lies the largest gypsum dune field in the world

Judy Underwood

White Sands from approximately 50 miles up. Notice Lake Lucero at lower left. (photo courtesy Google Earth)

(This is the first of two articles)

The Tularosa Basin is similar to the Salt Lake Basin in that there is no outlet. For the Salt Lake Basin the mineral that is famously concentrated is salt. For the Tularosa Basin the notable mineral is gypsum. These gypsum dunes cover 275 acres, the largest gypsum dune field in the world. Because of the strong southwest winds, the dunes are ever-changing. Last spring during the windy season fine gypsum was blown from White Sands to where I live in the Sacramento Mountains, more than 3,000 feet higher and 40 miles away.

Vegetation can stabilize the movement of the sand.

White Sands National Monument, established in 1933, lies between the San Andres Mountains to the west and the Sacramento Mountains to the east. Gypsum is a common element in these mountains. Over thousands of years, rains dissolved the gypsum and carried it to the Basin. With no river flowing out, the gypsum concentrated in the ancient lake, Lake Otero. Lake Otero filled the Basin for possibly 20,000 years. After the last ice age, about 12,000 years ago, Lake Otero began to dry up.

San Andres Mountains to the west, from White Sands.

Cottonwoods, with their deep roots, are able to grow in this harsh environment.

As Lake Otero evaporated, the dissolved gypsum became more concentrated, forming gypsum crystals: selenite. Selenite is named for Selene, the Greek goddess of the moon. The wind works on these crystals, slowly grinding them into sand, the White Sands. The lowest portion of the Basin sometimes has water and creates a temporary lake called Lake Lucero, which is much smaller than the ancient Lake Otero. When I was there recently, there was water in the lake.

View of Sierra Blanca, 60 miles to the northeast, across Lake Lucero

Once a month, weather permitting, there is a park ranger guided trip to Lake Lucero, the current source of the White Sands. The access road to the trailhead goes through White Sands Small Missile Range, which is not generally open to the public. After a drive of about 18 miles, the trail follows an arroyo down to the lake.

Trail from Lake Lucero

The selenite crystals form underground in the shape of a wheel. As the wind erodes the soil, the crystals are exposed and break apart. Action of the wind causes the crystals to disintegrate into sand. This is an ongoing process, with new crystals and new sand particles forming now.

Selenite crystals, about four inches long

European settlers in the late 1800s would dig up the selenite crystals to use as window glass.

The largest known selenite crystals are in Chihuahua, Mexico, in what is called the Crystal Cave. Some of the crystals are 36-feet long. There are two well-known caves, the Crystal Cave of the Giants and the Cave of Swords. Unfortunately, these are not hospitable tourist environments, because the temperature in the caves is about 136 degrees Fahrenheit with 100% humidity. The high temperature is thought to be a factor in creating these huge crystals.

Desert rose (not found at White Sands) is another form that selenite may take.

Balloon Festival at White Sands

At dawn, waiting for the balloons to launch

The famous balloon festival in New Mexico is the one in Albuquerque in October. White Sands has a small festival a week or two before the Albuquerque festival, in late September.

Other events at White Sands

In the summer, there are ranger-guided talks, star talks and full moon nights. The next moonlight bicycle ride is May 9, 2009 starting at 9pm.

Happy New Year from White Sands!

Next month, Part Two: White Sands Missile Range

January, 2009