When it comes to national parks in Colorado, Great Sand Dunes is usually an afterthought compared to the state’s flagship, Rocky Mountain. In recent years, the former has averaged about 500,000 annual visitors while the latter is regularly one of the most-visited U.S. national parks with about 4.5 million per year. But Great Sand Dunes National Park and Preserve has plenty to offer outdoor adventure enthusiasts, especially those touring Colorado for vacation.
The signature highlight—since the unit’s establishment in 1932—has long been a collection of the tallest sand dunes in North America, some reaching heights around 750 feet. Most visitors come to hike through the 30-square-mile dune field, while in recent years sand sledding and sandboarding have become increasingly popular. In the early 2000s, Great Sand Dunes was expanded, tripling in size to include a section of the adjacent Sangre de Cristo Range. Several longer trails allow visitors to explore the foothills and mountains rising above the dune field.
How the Dunes Formed
How this exceptionally tall dune field formed is a fascinating story of sand, water, and wind. Millions of years ago, the Sangre de Cristo Range was uplifted through tectonic processes. Rivers and streams carried eroded sediments like sand down from the mountains into the San Luis Valley, where they collected in an ancient lake. Over time, the lake dried up and disappeared, but the sediments remained. Next, the predominant winds from the southwest blew the sand to the northeast edge of the valley, where the dunes formed at the base of the Sangre de Cristo Range. Meanwhile, periodic storm winds swept over the mountains from the northeast. Together, these two opposing winds cause the dunes to grow to their remarkable heights.
Throughout the park, there are five primary types of dunes to spot. The most common are reversing dunes, created by the area’s reversing winds that build the dunes up to exceptional height and create a sharp crest called a Chinese wall. Star Dunes are a rare form with multiple arms created by changing wind directions, resulting in the very highest dunes in the park. Parabolic dunes look like crescents of sand, with the arms partly anchored by vegetation—found mostly to the southwest, outside the main dune field. Barchan dunes are another crescent-shaped feature created in areas where the wind mostly comes from only one direction, and examples can be found directly across from the main parking area. Finally, transverse dunes are a collection of barchan dunes that have aligned into a roughly linear feature perpendicular to the prevailing wind direction. To learn more about these dunes types, and how to find them in the park, stop by the visitor center.
Hiking the Great Sand Dunes
Today, visitors can explore anywhere in the 30-square-mile dune field. There are no designated trails, though there are some popular destinations. Due to high elevation, with the dune field mostly over 8000 feet, summer temperatures are quite pleasant, and daily highs typically range from the high 70s to low 80s. That said, due to sun intensity of Colorado in the summer, the afternoon temperature on the surface of the sand can reach 150 degrees! For that reason, it’s often best to explore the dunes during the morning.
Another hiking consideration is that the dunes, and therefore the common routes, change over time as the sand shifts. For that reason, the park service warns people against using maps or hiking apps that may have become out of date. Note that reaching the dune field from the visitor center and nearby parking lots requires wading across the typically shallow Medano Creek. The creek itself is a fun destination in its own right—particularly among kids—that’s popular for shallow dips to cool off and even inner tubing when there’s enough water. Peak flow in Medano Creek typically happens in early summer, and the park is very busy during that time, with the campground usually filled to capacity for this favorite Colorado weekend getaway.
The most common hiking destination within the dune field is called the High Dune on the First Ridge. Like the name suggests, this approximately 693-foot dune is the tallest one in sight from the main parking area (though it is not the tallest in the park). To reach it, cross Medano Creek and zigzag up the sandy ridgelines toward the visible summit. The round-trip distance is about 2.5 miles, but due to the exertion of hiking on loose sand, plus the elevation, it can take two or more hours to complete the route.
Since 2021, there have been two high points in the dune field, each 741 feet tall. The more accessible one is Star Dune, located less than 1.5 miles west of High Dune. While you can travel across the dune field between these two high points, the easier route is from the main parking area. Start by hiking south along Medana Creek south for about 2 miles, until a massive dune with a distinctive pyramid shape rises above all others to the north-northwest. Navigate along the ridgelines toward the summit. The round-trip distance is about 6 miles, which can take anywhere from 3 to 6 hours to complete.
In recent years, Hidden Dune has grown to equal heights as Star Dune. Hidden Dune is located toward the center of the dune field, and like the name suggests it is hidden from view and harder to find. From the main parking lot, it requires a 7-mile round trip hike, which can take from 3 to 6 hours to complete. Stop by the visitor center for more information if you want to visit Hidden Dune.
Other Activities: Sledding, Mountains, Camping, and More
In addition to hiking, sand sledding and sandboarding—basically like snowboarding on sand—have become popular activities in the dune field. Note that traditional snow sleds, snowboards, and skis will only slide on wet sand after rain or snowstorms, but the dunes are typically dry. For that reason, you’ll want specially designed sand sleds and sandboards, which have extra-slick base materials coated with a special type of wax. While savvy adventurers can build or convert their own equipment, most visitors prefer to rent equipment from shops located outside the park.
If the dunes are too hot for hiking, there are several trails leading into the Sangre de Cristo Range. The Mosca Pass Trail is 3.5 miles, one-way, with about 1,500 feet of elevation gain, that follows a small creek to a mountain pass. The Sand Ramp Trail is 11 miles, one-way, following the foothills just outside the dune field. This trail can be used to access several other trails, including the short Dunes Overlook Trail, with total mileage being 2.5 miles round-trip. There are several other more challenging hiking trails through the mountains, which either require long-distance backpacking or driving the Medano Pass Primitive Road (4WD required), where fat-biking is also possible. There are also 21 first-come free campsites along the primitive road.
One mile north of the visitor center, the Piñon Flats Campground has 91 sites for tents, with some sites suitable for small RVs (up to 35 feet, no hookups), that are open from April through October. All campsites must be reserved on Recreation.gov, up to six months in advance. The campground has a store and flush toilets but no showers. Yet another excellent option for Colorado camping during your national parks road trip!
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Lead photo: A hiker surveys the dunes. NPS/Patrick Meyers