Great Sand Dunes National Park
Great Sand Dunes National Park and Preserve stands as one of Colorado's most striking natural wonders, preserving the tallest sand dunes in North America along the eastern edge of the San Luis Valley, tucked against the base of the rugged Sangre de Cristo Mountains. The park conserves an area of large sand dunes on the eastern edge of the San Luis Valley, with an adjacent national preserve in the Sangre de Cristo Range, in south-central Colorado. The park contains the tallest sand dunes in North America, up to 750 feet (230 m) tall. What began as a national monument in 1932 grew over the following seven decades into a full national park and preserve, encompassing an extraordinary range of ecosystems — from arid dunefield and grassland to alpine tundra and snowcapped peaks.
Geography and Physical Setting
Great Sand Dunes National Park and Preserve is located in Saguache and Alamosa Counties, Colorado. The national park occupies the San Luis Valley while the national preserve lies to the east in an adjacent section of the Sangre de Cristo Range of the Rocky Mountains. Elevations range from 7,515 ft (2,291 m) in the valley west of the dunes, to 13,604 ft (4,146 m) at the summit of Tijeras Peak in the northern part of the preserve.
The park encompasses 107,342 acres (167.7 sq mi; 434.4 km²) while the preserve protects an additional 41,686 acres (65.1 sq mi; 168.7 km²) for a total of 149,028 acres (232.9 sq mi; 603.1 km²). The dunes cover an area of about 30 sq mi (78 km²), while the surrounding relatively flat sand sheet, which feeds the large dunes, is actually the largest component of the entire dunes system, containing about 90% of all the sand in the park.
The nearest major city is Alamosa, providing essential services for the many visitors who travel to the park each year. The nearest city is Alamosa, which is about 30 mi (48 km) away by road to the southwest. Adjacent protected lands include the Baca National Wildlife Refuge to the west and the Rio Grande National Forest to the north and southeast.[1]
Geology and Dune Formation
Recent scientific research suggests that the Great Sand Dunes in Colorado began forming around 440,000 years ago, after a large inland lake that once covered the San Luis Valley — named "Lake Alamosa" when evidence of the lakebed was discovered in 2002 — dried up due to climate change. The sand left behind by that ancient lake became the raw material for one of the continent's most dramatic geological features.[2]
The mechanics of dune formation at this site are unusually complex, driven by opposing wind systems. The dune field itself lies in a pocket within the Sangre de Cristo Mountains because southwesterly winds push the sand into this natural entrapment. Wind from the northeast funnels through the Sangre de Cristo Mountains and pushes against the opposing southwestern winds, which erodes additional sand from the mountain sides and brings it into the dune system. This back-and-forth switching of wind direction builds dunes on top of each other instead of pushing them continually forward.
Water also plays an essential role in keeping the dunes stationary. Another source of sand into the dune system is sediment runoff from the surrounding mountain ranges. Medano Creek and Sand Creek continually capture windblown sand from the mountains, collect new sediments, and carry it back down to the base of the dunes. This perpetual cycle of wind and water recycling is what has allowed the dunefield to maintain its extraordinary height over hundreds of thousands of years.
The tallest dune, Star Dune, measures 755 feet from its base. According to a study conducted by the National Park Service, Great Sand Dunes is the quietest national park in the contiguous United States.[3]
History
Indigenous and Early American History
Human presence at the Great Sand Dunes stretches back thousands of years. The oldest evidence of human inhabitants on the dunes dates back nearly 11,000 years. From Native American traditions from the Navajo, Apache, and Ute tribes, to European and American settlers and homesteaders, these sand dunes have provided home and wonder to many groups over the centuries. Archaeological remains of the prehistoric Clovis complex have been recovered from the area, which in historic times was the domain of Ute peoples.
Lt. Zebulon Pike was the first recorded American explorer — in January 1807 — to cross the Sangre de Cristo Mountains to the Great Sand Dunes. Pike and his men were exploring the Louisiana Purchase Territory under orders from President Thomas Jefferson.[4]
The Great Sand Dunes also serve as a cultural crossroads for more than 10,000 years of human history, from Paleolithic big-game hunters to nomadic Native Americans, Spanish conquistadors, transcontinental explorers, hard rock miners, and modern-day tourists.
From National Monument to National Park
The site was originally designated a national monument in 1932 to protect its dunes from gold mining and sand extraction for cement, but for millennia before the designation, indigenous communities had viewed the sand dunes as a sacred place. 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 (55.5 sq mi; 143.8 km²).[5]
Threats to the regional water supply proved to be a catalyst for expanding the park's protections. In 1986, a plan by American Water Development Inc. (AWDI) to pump groundwater from the San Luis Valley to the growing cities of Colorado's Front Range sparked an extended legal battle over water rights. Scientific data accumulated by the National Park Service for the court case against AWDI indicated the presence of a much larger aeolian system responsible for the existence of the dunes, encompassing distinct ecosystems stretching from the mineralized hardpan and vast sand sheet west of the main dunefield all the way to the crest of the Sangre de Cristos. More importantly, the data proved that the Great Sand Dunes were hydrologically connected to the San Luis Valley's surface and groundwater.
In the aftermath of these threats to San Luis Valley water, resource management staff at the Great Sand Dunes — along with a coalition of concerned citizens, conservancy groups, NPS officials, and local, state, and federal politicians — concluded that the best way to ensure perpetual protection for the entire Great Sand Dunes ecosystem was to expand the boundaries of the protected area and designate it a national park.
The eventual redesignation as Great Sand Dunes National Park and Preserve was authorized on November 22, 2000, when President Bill Clinton signed the Congressionally approved Great Sand Dunes National Park and Preserve Act. A key step in assembling enough land was a major real estate transaction by a private conservation organization: in 2002, the Nature Conservancy purchased the Baca Ranch — an area of 97,000 acres (151.6 sq mi; 392.5 km²) — for $31.28 million. Financing was provided by the Department of the Interior, the Colorado State Land Board, and private donors. Great Sand Dunes was formally made a national park on September 13, 2004.[6]
Ecology and Wildlife
The park encompasses a remarkable diversity of life zones, from desert-like dunes at the valley floor to alpine terrain in the preserve. With the passage of the Great Sand Dunes National Park and Preserve Act, resources now also include alpine lakes and tundra, six peaks over 13,000 feet in elevation, ancient spruce and pine forests, large stands of aspen and cottonwood, grasslands, and wetlands — all habitat for diverse wildlife and plant species.
Several types of grasses, the kangaroo rat, and some insects survive on the relatively stable dunes. The lower slopes of the Sangre de Cristo are forested in pine, cottonwood, and aspen, which give way higher up to spruce and fir. At successively higher elevations are found subalpine meadow and alpine tundra plant communities that in summer abound in wildflowers.
The park's broader corridor is vital for large mammals and rare fish species alike. The valley is located at the uppermost terminus of a major wildlife corridor along the Upper Rio Grande river that stretches into New Mexico. The corridor is vital for elk, bighorn sheep, bobcat, black bear, mountain lions, and the rare Rio Grande cutthroat trout.
After dark, the dunes host their own distinct community of nocturnal life. Night-life of the dunes includes camel crickets, kangaroo rats, toads, salamanders, coyotes, bobcats, and owls. In recent years, a large number of elk have sought refuge inside the areas of the park where hunting is not permitted.[7]
Recreation, Stargazing, and Visitor Experience
Great Sand Dunes National Park draws hundreds of thousands of visitors annually. Almost half a million people travel to this park every year for its unique landscape, and those visitors spend $27 million annually in nearby communities.
The dunes themselves are the primary draw. Visitors may climb, sled, or sandboard the massive formations with no designated trail system across the dunefield. Sandboarding and sand-sledding at the Great Sand Dunes National Park is a highlight for many families. Medano Creek, which runs seasonally at the base of the dunes in spring and early summer, adds yet another dimension to the visitor experience; the seasonal Medano Creek creates a temporary beach environment at the base of the massive sand formations.
For those seeking more structured adventure, visitors can also find picnicking, hiking, and camping opportunities, the challenging four-wheel scenic drive on Medano Pass, horseback-riding trails, and some 14,000- and 13,000-foot peaks for highly skilled mountaineers to climb, including Crestone Needle, Crestone Peak, Cleveland Peak, and Mount Herard. The Piñon Flats Campground is run by the National Park Service, with 88 total campsites — 44 that are first-come, first-served and 44 that visitors can reserve in advance.[8]
The park is also a premier destination for stargazing. With a combination of dry air, little light pollution, and high elevation, Great Sand Dunes National Park and Preserve is an excellent and easily accessible dark sky viewing location. In 2019, Great Sand Dunes was certified as an International Dark Sky Park by the International Dark Sky Association. Due to the intervening Sangre de Cristo Mountains, which shelter the park from much of the sky glow created by Colorado's Front Range cities, Great Sand Dunes has served as an astronomy destination for decades. Great Sand Dunes was certified as a Gold Tier, International Dark Sky Park in 2019, meaning that due to its remote location and measures taken within the park to limit the use of outdoor lights, the area is free of light pollution and therefore a pristine place to observe the night sky.[9][10]
Sand surface temperatures can reach 150°F in the summer, more than hot enough to burn the feet of both people and dogs — a safety consideration that the National Park Service actively communicates to visitors, particularly those who plan midday excursions onto the dune face.
The Great Sand Dunes National Park is open 24 hours a day, 365 days a year.[11]