Great Sand Dunes National Park and Preserve

Great Sand Dunes National Park and Preserve is United States National Park located in the southern part of the U.S. state of Colorado in the American Southwest. It was created by an act of Congress on September 13, 2004, making it the newest national park in the United States. The park contains approximately 85,000 acres (340 km²).

Natural history

The park contains the tallest sand dunes in North America, rising about 750 feet (230 m) from the floor of the San Luis Valley on the western base of the Sangre de Cristo Range, covering about 19,000 acres (78 km²). They are perhaps 12,000 years old.

The dunes were formed from sand deposits of the Rio Grande River and its tributaries, flowing through the San Luis Valley. Over the ages, westerly winds picked up sand particles as they flew over the Rocky Mountains from the river flood plain. As the wind lost power before crossing the Sangre de Cristo Range, the sand was deposited on the east edge of the valley. This continues, and the dunes are slowly growing by the wind that daily changes the shape of the dunes. There are areas of black sand which are deposits of magnetite, a crystalline black oxide of iron.

The dunes form because as the wind blows sand and small rocks across the valley and up against Colorado's Sangre de Cristo Range, it slows and drops the debris. Like snow drifting behind a snow fence, the blowing sand is blocked by the mountains and accumulates at their base. There are several streams flowing on the perimeter of the dunes. The streams erode the edge of the dune field, and sand is carried downstream. The water disappears into the ground, depositing sand on the surface. Winds pick up the deposits of sand, and blow them up onto the dune field once again.

Digging a few inches into the dunes even at their peaks reveals wet sand. If the streams were to dry up, the dunes would disappear; in fact part of the motivation of turning the Monument into a National Park was the extra protection of the water, which Colorado's cities and agriculture covet.

It is very easy to experience the dune-building process. This is a very windy region, as hikers on the Sand Dunes will attest, as on many days they will be pelted by sand and even small rocks when hiking on the dunes. The wind carries sand and rocks from many miles away.

Other features

The park also contains alpine lakes and tundra, six peaks over 13,000 feet (3,940 m) in elevation, ancient spruce and pine forests, large stands of aspen and cottonwood, grasslands, and wetlands — all habitat for diverse wildlife and plant species.

One of the most unusual features of the park happens at Medano Creek, which borders the east side of the dunes and is located next to the Visitor Center and Bookstore. Because fresh sand continually falls in the creek, Medano Creek never finds a permanent and stable streambed. Small underwater sand dunes that act like dams continually form, and break down. So waders in the stream see surges—which look like waves—of water flowing downstream at intervals of just a few seconds to a minute or more. In a high-water year, these surges can be as much as a foot in height, resembling ocean waves. Building sand castles with the creek sand is a popular visitor activity.

Access

Getting to the dunes requires walking across the wide and shallow Medano Creek, which only flows spring to early summer. Hiking is permitted, with the warning that the sand can get hot in the summer, up to 140° Fahrenheit (60° Celsius). The area gets snow in the winter.

The closest city is Alamosa, though Pueblo, Colorado Springs, Denver and Albuquerque, New Mexico are not far off.

Park history

The dunes and surrounding area were designated a National Monument in 1932. On November 22 2000, United States President Bill Clinton signed the Great Sand Dunes National Park and Preserve Act of 2000, aiming at ultimate national park status. With the help of the Nature Conservancy, the federal government purchased 97,000 acres of the Baca Ranch, which in effect tripled the size of the park. The purchase includes those sections of the ranch which previously bordered the park on the north and west sides and also included fourteener, Kit Carson Mountain (14,165), Challenger Point (14,080) and the water drainages to the south. The land purchased was split into three sections, the part of the Sangre de Cristo Mountains would be transferred to the Rio Grande National Forest, another section to the west would be set aside as a wildlife area and would host a wild bison herd and the last section to the east would be transferred from the Rio Grande National Forest and would be open to some hunting.

External links and references

National Parks of the United States | National parks in Colorado | National Preserves of the United States | Alamosa County, Colorado | Saguache County, Colorado

Great-Sand-Dunes-Nationalpark | Great Sand Dunes National Park and Preserve | グレートサンドデューンズ国立公園 | Park Narodowy Great Sand Dunes

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Natural history

Other features

Access

Park history

External links and references