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Great Sand Dunes National Monument and Preserve - History
By Sarah Lane
Jan 31, 2005, 14:30

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Great Sand Dunes National Monument and Preserve - History


Tucked against the Sangre de Cristo Mountains in south-central Colorado, the San Luis Valley is home to the tallest sand dunes in North America. Reaching heights of over 700 ft., the
Great Sand Dunes National Monument and Preserve is constantly being restructured by the southwest winds that blow across the valley. The massive dunes hide a complicated system of wind, erosion, and sand deposition. For several thousand years westerly winds have traveled over the Rockies and down over the river flood plain, picking up sand particles from the valley and the Rio Grande River. The winds then deposit the finely-ground pumice, ash, quartz, and lava at the eastern edge of the valley before it rises to cross the Sangre de Cristo mountains. The process continues and as you can see, the seemingly tiny sand particles group together to form the continuously changing dunes.

This National Monument was designated by proclamation of President Herbert Hoover in 1932 as our 36th National Monument. On November 22, 2000, President Clinton signed the Great Sand Dunes National Park and Preserve Act of 2000, which authorized the expansion of the National Monument into a National Park almost four times its original size. This enlarged the area to 60 square miles or just over 38,660 acres. With this new addition the park’s resources now include alpine lakes and tundra, six peaks over 13,000', ancient spruce and pine forests, and large stands of aspen and cottonwood, grasslands, and wetlands.


Indian rice grass, blowout grass, scurf pea, and prairie sunflower are just a few of the twenty different species of plants growing directly on the Great Sand Dunes. They are a habitat for unusual plant communities and globally rare species like the Slend spider flower.
Six species of insects live here that are not found anywhere else in the world including the Great Sand Dunes tiger beetle. Also part of the landscape are the mammals. Ord’s kangaroo rats, silky pocket mice, plains pocket mice, northern pocket gophers, mule deer, rabbits, ground squirrels, coyotes, pronghorn antelope, and chipmunks are just a few of the creatures cruising around the terrain. You’ll also find several types of ducks and birds including golden eagles, red-tailed hawks, owls, swifts, mountain bluebirds, and western tanagers.

Aside from the attributes already mentioned, this park also contains the largest known stand in the United States of ponderosa pine trees bearing ancient tribal markings. Another amazing feature of the Great Sand Dunes is Medano Creek. This crazy stream starts in the Sangre de Cristo mountains, flows along the eastern edge of the dunes, and periodically disappears below ground in the valley. You can be standing in a fast-moving current measuring over a foot deep and then suddenly the water will stop and flow several meters away instead.

You can learn more about the amazing features of this National Monument by checking out our Resources and Tourism links. Now that you know all about these dunes, take our quiz!

Source: National Park Service, American Southwest





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