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Great Sand Dunes National Park and Preserve

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Great Sand Dunes National Park and Preserve
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LocationSaguache County & Alamosa County, Colorado, USA
Nearest cityAlamosa
Area84,670 acres (342.6 km2)
EstablishedSeptember 13, 2004
Visitors258,660 (in 2006)
Governing bodyNational Park Service

Great Sand Dunes National Park and Preserve is a United States National Park located in the easternmost parts of Alamosa County and Saguache County, Colorado, United States. Originally designated Great Sand Dunes National Monument, Great Sand Dunes National Park and Preserve was created by an act of the United States Congress on September 13, 2004. The park contains approximately 85,000 acres (340 km², 130 mi²).

File:ClimbingGreatSandDunesNP.JPG
Climbing 700 foot dunes

Natural history

Satellite image of the dunes

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 (77 km²). They are perhaps 12,000 years old.

The dunes were formed from sand and soil deposits of the Rio Grande and its tributaries, flowing through the San Luis Valley. Over the ages, westerly winds picked up sand particles 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 process continues, and the dunes are slowly growing. The wind changes the shape of the dunes daily.

Great Sand Dunes

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. 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.

The dunes contain areas of black sand which are deposits of magnetite, a crystalline black oxide of iron.

Other features

The intermittent Medano Creek
View from a high dune

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. Skimboarding is great activity for young people to do here because they only need an inch or two in creek depth.

One of the most valued features of the Great Sand Dunes National Park and Preserve is one that you can't see. According to a recent Soundscape Study conducted by the National Park Service, this park is the quietest national park in the 48 contiguous United States.

Access

Getting to the dunes requires walking across the wide and shallow Medano Creek, which flows only from 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 Canon City, Pueblo, Colorado Springs, Denver and Albuquerque, New Mexico are within a few hours drive. The U.S. Post Office at Alamosa (ZIP Code 81101) serves the national park.[1]

Park history

The dunes — 750 feet (230 m) tall — at the base of the Sangre de Cristo Range.

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 (390 km2) 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 14,165 feet (4,317 m) Kit Carson Mountain and 14,080 feet (4,292 m) subpeak Challenger Point, and the water drainages to the south. The land purchased was split into three sections. 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.

References

  1. ^ "ZIP Code Lookup" (JavaScript/HTML). United States Postal Service. January 3, 2007. Retrieved January 3, 2007.