Great Sand Dunes National Park and Preserve is a United States
National Park located in the easternmost parts of Alamosa County
and Saguache County
, United States. Originally created as Great Sand Dunes National Monument
on March 17, 1932.The park includes 44,246 acres (17,906 ha) and the preserve protects an additional 41,686 acres (16,870 ha). It is the newest of the United States National Parks.
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 km sq). Researchers say that the dunes started forming less than 440,000 years ago.
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.The dunes contain areas of black sand which are deposits of magnetite, a crystalline black oxide of iron.
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, and so waders in the stream see surges—which look like waves—of water flowing downstream at intervals of anywhere from 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, and Skimboarding is a great activity for young people to do because only an inch or two of creek depth is needed.One of the most valued features of the Great Sand Dunes National Park and Preserve is one that can't be seen. 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
.Many visitors to the site try to sled down the dunes. The Park Service provides hints as to the best time to sled (when the sand is wet) and which equipment works best.Visitors anytime other than late fall through early spring are also advised to avoid bare feet or sandals, and stick with sturdy, closed footwear. While the sand looks alluring, its chocolate color absorbs heat. The daylight sand temperature can reach 140 degrees and will burn bare feet.
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
, Colorado Springs
and Albuquerque, New Mexico
are within a few hours drive. The U.S. Post Office at Alamosa (ZIP Code 81101) serves the national park.