Great Sand Dunes National Park


National Parks Image Gallery In the foreground are the amazing sand dunes for which the park is known. Behind the dunes are the Sangre de Cristo Mountains and sloping alpine tundra. See more pictures of national parks.
©2006 National Park Services

Great Sand Dunes National Park

11500 Highway 150

Mosca, CO 81146-9798

719-378-6300

www.nps.gov/grsa

In the shadow of the Sangre de Cristo ("Blood of Christ") mountains in southern Colorado, Great Sand Dunes National Park is home to the tallest dunes in North America. Travelers from Albuquerque, Colorado Springs, and Denver can reach the park in under four hours by car. The best way to explore the sand dunes is is by foot, although a primitive road to Medano Pass provides a scenic tour for all-terrain vehicles.

Entrance fees: $3/individual for seven days; individuals 16 years old and younger are free.

Visitor center: The visitor center is open daily, except January 1 and December 25.

Accommodations: Pinyon Flats campground. Open year-round. First-come, first-served.

©2006 Publications International, Ltd.

Visiting Great Sand Dunes National Park

Great Sand Dunes National Park encompasses more than 30 square miles of dunes, plus alpine lakes and tundra, desert valley, the Sangre de Cristo mountains, ancient spruce and pine forests, grasslands, and wetlands. Naturally, a host of animals, trees, and other vegetation have found a home on this land, which supports several rare biological communities. Within the park's confines are some of the oldest archeological sites in America, indicating that humans inhabited this land as long as 9,000 years ago.

The rich biodiversity, cultural history, and scenic splendor of Great Sand Dunes National Park draw travelers to this recently established park. On the next page, you can find out what to see and do at Great Sand Dunes.

Sightseeing at Great Sand Dunes National Park

©2006 National Park Services Cleveland Peak presides over the Great Sand Dunes.

Great Sand Dunes National Park's dunes are the product of competing elements: wind and water. Winds of more than 13 miles per hour from the southwest and northeast shake loose available sand, blowing it into one of three deposits in the valley: the cementlike sabkha, the outer sand sheet, and the inner dunefield (home of the biggest dunes).

Medrano and Sand creeks also carry sand from the dunefield's north and east borders, transporting it back to where the wind can blow it into the heart of the dunes. All in all, the dunes contain nearly five billion cubic meters of sand.

Above the dunes, the park and preserve also include a parcel of alpine tundra, complete with a number of lakes, and six peaks over 13,000 feet in elevation. The forests here, populated by spruce, pine, aspen, and cottonwood, are bordered by grasslands and wetlands, making good habitat for a wide variety of life.

The park's animal residents include mule deer, elk, coyotes, and bald eagles; bison graze on the adjacent grassland. A number of insect species found in the dunes, such as the Great Sand Dunes tiger beetle and the giant sand treader camel cricket, live nowhere else on Earth.

Great Sand Dunes National Park Photo Opportunities

Hiking in the dunes is well worth the effort because of the amazing views, with the summit of High Dune offering the best panorama. For visitors with more time to spend, there are also plenty of hiking trails in the surrounding wilderness. Below, we list some of the best places to practice the art of photography.

  • High Dune: Although not the highest dune in the park, High Dune is the tallest dune visible from the visitor center, offering a 650-foot elevation boost. There are no trails to reach the top, so motivated hikers follow the ridge lines, zigzagging to the summit. A sweeping view over the sand dunes awaits those who make the climb.
  • Mosca Pass Trail: Stealthy hikers may observe weasels, pine martens, mountain lions, red foxes, or black bears. The path follows Mosca Creek through pinon-juniper woodlands, aspen groves, grassy meadows, and spruce-fir forest.
  • Zapata Falls: The 30-foot Zapata Falls pour from a rock crevasse into a pool of icy water. This is a particularly good excursion for a hot summer day, as the trail to the falls passes through a stream (wading is required). From the Zapata Falls alcove, hikers are rewarded with clear views of the Great Sand Dunes, San Juan Mountains, Sangre de Cristo Mountains, and San Luis Valley.
  • Music Pass: It's a steep 3.5-mile climb from the lower parking lot to Music Pass, but the panoramic views are spectacular. Depending on the direction you face, you'll see the Tijeras and Cleveland peaks, Music Mountain, Wet Mountain Valley and upper Sand Creek Valley.

There are a variety of activites for visitors to enjoy, including sand-castle building in the endless hills of sand. But where did all this sand come from, and how do the dunes assume their unusual shapes? To learn about the formation of these sand dunes, go to the next page.

History: How the Great Sand Dunes Were Formed

©2006 National Park Services Upper Sand Creek Lake feeds Sand Creek, which carries new sand to the valley and its dunes.

The magnificent sand dunes are, of course, the main attraction at Great Sand Dunes National Park. Scientists believe that the sand that comprises the dunes has been in the San Luis Valley for 35 million years. According to their theory, volcanoes erupted where the San Juan Mountains now stand, spewing ash-flow tuff and sediment into the valley.

Subsequently, the Sangre de Cristos uplift occurred beneath the valley floor, and sediment filled in the widening Rio Grande rift. The resultant substratum of rock under ash-flow tuff under sediment gave rise to the sand dunes we see today.

The dunes are shaped by winds blowing across the landscape. These winds slowly shift the face of the dunes and add new sands that have been deposited by the Medano and Sand creeks. Varying wind patterns create an array of dune designs:

  • Reversing dunes: These are the largest dunes. They are a product of winds blowing predominately in opposite directions.
  • Star dunes: The many "arms" of star dunes are shaped by winds blowing in all directions.
  • Parabolic dunes: Oblong designs are formed when vegetated sand prevents parts of the dune from migrating.
  • Barchan dunes: The half-moon shape of the barchan dune is created when "perfect" conditions -- flat land, unidirectional wind, and no vegetation -- occur.
  • Transverse dunes: Transverse dunes are a series of barchan dunes aligned along a line.

It is fascinating to seek out each type of dune and try to imagine the forces that created it. The far northeast corner of the dunefield is known for its complex of star dunes, and parabolic dunes are commonly formed in the sand sheet southwest of the main dunefield. Barchans may be seen directly across from the dune's main parking lot, and along the southern boundary of the dunefield a series of transverse dunes can be observed.

Surge FlowAnother fascinating natural feature that visitors can observe is the pulsating flow of the Medano and Sand creeks. The creeks' surge flow is unique, and this is the only location in North America where the three elements necessary to create the rhythmic waves are present: sufficient water to produce surges, a steep enough grade to give a stream a higher velocity, and a smooth and mobile surface that has little resistance.

The actual pulse is caused when a dam breaks, releasing a wave of water. As water flows across the sand, sand dams, or antidunes, form beneath the surface of the water. The antidune is slowly built up as more sand collects on it, and the volume of water dammed behind the antidune increases accordingly. Eventually, the trapped water becomes heavy enough to break through the antidam, and the creek experiences a surge, or pulse.

Behind the sand dunes, the Sangre de Cristo Mountains create a dazzling backdrop. This fascinating profusion of geology and nature create a unique national park in southern Colorado, where learning and exploring opportunities abound. Visitors seeking solitude and escape from urban life revel in the striking scenery that makes up Great Sand Dunes National Park.©Publications International, Ltd.