Monday, January 3, 2011

Harshest of Conditions

We headed east of Las Cruces on Highway 70, passing through a vast area of desert and mountain ranges 100 by 40 miles in extent. This is the 4,000-square-mile White Sands Missile Range, which completely surrounds the White Sands National Monument. The range continues to be an important testing site for experimental weaponry and space technology, so the highway is usually closed a couple of times a week for one to two hours.

The largest pure gypsum dune field in the world is located at White Sands. "The gypsum was deposited at the bottom of a shallow sea some 250 million years ago. Eventually turned into stone, gypsum-bearing marine deposits were uplifted into a giant dome 70 million years ago when the Rocky Mountains were formed. Beginning 10 million years ago, the center of the dome began to collapse and create the Tularosa Basin. The remaining sides of the original dome formation now form the San Andres and Sacramento mountain ranges.

"Rain and snow dissolve gypsum from these mountains and carry it to the Basin where it is trapped. The edge dunes are just a few feet high and support some plant life, with several species of grass, yucca and saltbush managing to survive at scattered points."

The second trail that we came to after leaving the Visitor Center was the Dune Life Trail. Just inside the southeast edge of the dunes, this trail loops for one mile around an area where the landscape is heavily vegetated.

As the infor-mational brochure notes: "Venturing out onto any of our five established trails provides you with a first-hand opportunity to experience the timeless majesty and wonder of the dunes."

Our introduction to the dunes was this trail and the surrounding area where foot traffic is quite heavy. The vegetation, whether in the form of larger groupings or single plants, presented an environment rich in subject matter for photographers.

This trail provided many oppor-tunities for a close-up view of this vegetation. Here the dunes provided background for the groupings and muted colors of the plant life that survives in such a harsh environment.

"Harsh" to say the least. The highly mineralized water table under these soils ranges from about 3 feet below the surface at the interdune flats to more than 20 feet outside the dune field.

Plants surviving here must also endure being buried by moving dunes and be able to tolerate extreme fluctuations in temperature, with common sub-freezing winter lows to occasional 100+ summer days.

Interest in some sort of national recognition for the dunes grew throughout the latter part of the 1920s.

Studies were conducted by the National Park Service that determined that while the dunes might not meet the criteria for National Park status, which required a variety of resource values, the setting was ideal for preser-vation as a national monument.

Formal recognition for the uniqueness of the white sands of southern New Mexico came on January 18, 1933, when President Herbert Hoover proclaimed and established a White Sands National Monument.

Tomorrow's photos will feature the dunes along another trail.

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