Great Sand Dunes National Park and Preserve — dune
Image by RJA1988 from Pixabay

Great Sand Dunes National Park and Preserve

  • 2 min read
  • 37.834° N 105.497° W
  • Dark Sky Place

Interesting facts

  • The dunes stay moist year-round: under a thin dry crust the sand holds about 7% water, which helps them grow so tall.
  • Almost 90% of the park's sand lies not in the dunes but in the flat sand sheet of grassland around them.
  • In summer the sand surface can heat up to about 66 °C (150 °F) on sunny afternoons.
  • The Ute name for the dunes means "sand that moves", while the Jicarilla Apache name means "it goes up and down".
  • Humans have lived around the dunes for about 11,000 years; the first visitors were Clovis and Folsom hunters of mammoths and bison.
  • The first known written description of the dunes is in the journals of the explorer Zebulon Pike, who crossed the mountains just above them in 1807.
  • In 1932 a mining company built a mill to extract gold from the dune sand, but recovered only minute amounts.
  • Fear that gold mining or concrete-making would destroy the dunes led local women of the P.E.O. Sisterhood to push for protection.
  • The valley was once covered by a vast ancient lake, Lake Alamosa, which drained about 440,000 years ago through the Rio Grande.
  • More than 2,000 bison graze within the park boundary on a ranch owned by The Nature Conservancy.

Why it is worth it

At the eastern edge of Colorado's broad San Luis Valley, a sea of sand rises against the Sangre de Cristo Mountains as if it had been poured there. These are the tallest dunes in North America: the Star Dune reaches about 229 metres (750 ft) from base to crest, and the whole dunefield covers some 30 square miles holding billions of cubic metres of sand. The setting is what makes them unforgettable. You stand on bare, rippled sand at over 2,300 metres, with peaks of more than 13,000 feet directly behind and a creek running across the foot of the dunes.

Their origin is a story of wind and water working against each other. Sediment washed from the surrounding mountains filled the valley, and when an ancient lake there drained, the exposed sand was blown by the prevailing southwesterly winds toward the mountains, which trap it in a natural pocket below the passes. Storm winds from the opposite direction push the sand back, so the dunes grow upward instead of migrating away.

In late spring, snowmelt turns Medano Creek into one of the park's curiosities: shallow water spreads across the sand and moves in pulsing "surge flows", small waves arriving roughly every twenty seconds as sand ridges build and collapse on the creek bed. It peaks from late May into early June. At other times the draw is the climb itself — there are no marked trails on the dunes, and people hike, sandboard and sled down the slip faces. The preserve reaches up into alpine forest, tundra and lakes, and more than 250 bird species have been recorded, along with elk and an endemic tiger beetle found nowhere else.

Protected as a national monument in 1932, the area became a national park and preserve in 2004, and in 2019 it was named an International Dark Sky Park; at night the dunes lie under a sky with almost no artificial light. The best light for photography is early and late in the day, when low sun carves the ridges into sharp shadow lines.

Getting there

The dunes lie in the San Luis Valley in southern Colorado. The nearest town of any size is Alamosa, about 30 miles (roughly 50 km) away by road; Cañon City is about 71 km in a straight line but on the far side of the mountains. San Luis Valley Regional Airport (ALS) in Alamosa is about 55 km away. By car, the approach is from US Highways 160 or 285 and then Colorado Highway 150 to the visitor centre. The 22-mile Medano Pass Road is a high-clearance 4WD route open seasonally.

On these lists

The Most Beautiful Places in Colorado 14The Most Beautiful Places in the United States 228The Most Beautiful Dunes 16The Most Beautiful Natural Wonders in the United States 68The Most Beautiful Natural Wonders 580

From the encyclopaedia

Great Sand Dunes National Park and Preserve is a national park of the United States that conserves an area of large sand dunes on the eastern edge of the San Luis Valley, and an adjacent national preserve in the Sangre de Cristo Range, in south-central Colorado. The park was originally designated Great Sand Dunes National Monument on March 17, 1932, by President Herbert Hoover. The original boundaries protected an area of 35,528 acres. A boundary change and redesignation as a national park and preserve was authorized on November 22, 2000, and then established on September 24, 2004. The park encompasses 107,342 acres while the preserve protects an additional 41,686 acres for a total of 149,028 acres. The recreational visitor total was 527,546 in 2019.

Wikipedia · CC BY-SA 4.0

37.83361, -105.49670per Wikidata