Great Sand Dunes National Park
Great Sand Dunes National Park | ||
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Dune panorama in the park | ||
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Location: | Colorado , United States | |
Next city: | Alamosa | |
Surface: | 434.40 km² | |
Founding: | September 13, 2004 | |
Visitors: | 442,905 (2018) | |
Address: | Great Sand Dunes National Park | |
The Great Sand Dunes (German Large Sand Dunes ) are a national park ( National Park and Preserve ) designated protected area in the southern part of the US state of Colorado . About 230 km south of Denver are the Great Sand Dunes in the northeastern part of the San Luis Valley , a basin up to 60 kilometers wide between the Sangre de Cristo Range and the San Juan Mountains . They cover an area of around 80 km² and are the highest dunes in North America with a height of around 230 meters .
history
The sand dunes are around 12,000 years old and were created by sand deposits from the Rio Grande and its tributaries. For thousands of years, westerly winds have blown the grains of sand from the river banks through the valley and deposited them on the east side at the foot of the Sangre de Cristo Range . The mountains slow down the wind speed and the sand and small stones have piled up to form dunes. This process continues and changes the shape of the dunes every day.
Through many small streams in the San Luis Valley , the sand soaks up water , which makes it heavier and can no longer be carried away by the winds. Even at the highest point of the dunes, the sand is moist a few inches below the surface. Since the dunes would also disappear over time as the streams dried up, ensuring the water supply was one reason for the establishment of the higher protection status as a national park in 2000.
An extraordinary phenomenon can be seen in Medano Creek , a creek east of the dunes near the visitor center. Because fresh sand trickles evenly into the water, the stream does not find a stable and permanent river bed . This creates small underwater dunes that form dams and collapse again. This creates surf waves at intervals, which can be up to 30 centimeters high at times when the water level is high.
National park
The area around the dunes was declared a National Monument on March 17, 1932 . On 22 November 2000 the then signed US President Bill Clinton a law establishing the National Park ( Great Sand Dunes National Park and Preserve Act of 2000 ) after the land area of the protected area was enlarged and the Congress had approved the bill. The extension areas are subject to the lower protection status of a National Preserve ; hunting is permitted here. The national park was officially opened on September 13, 2004 .
See also
Web links
- National Park Service: Great Sand Dunes National Park (official site; English)