The Tallest Sand Dunes in North America Have a Seasonal ‘Beach’ That Only Appears Once a Year—What to Know

Located in southern Colorado’s San Luis Valley, Great Sand Dunes National Park & Preserve is home to North America’s tallest sand dunes. These dunes, which rise abruptly from the shadow of Colorado’s Sangre de Cristo Mountains, are formed by the interplay of winds funneling through mountain passes and the ongoing recycling of sand via wind. While the star attractions, Hidden Dune and Star Dune, tower approximately 750 feet above the valley floor, one of the park’s extraordinary features is Medano Creek, a seasonal stream that emerges in spring and early summer.

Fed by snowmelt, Medano Creek—called Colorado’s Natural beach—flows at the dunes’ base, creating a shallow, inland beach-like playground where visitors can splash, float on tubes, and build sandcastles. The flow typically begins in late April and peaks by early June, with water depths reaching ankle to calf level—often around 20 inches—before drying out during mid-summer.

Visitors flock to the dunes when the creek is in bloom as well as for exhilarating activities such as sandboarding, sledding, and dune hiking. It’s worth noting that, on warm days, sand surface temps can soar to 150 degrees, so hiking shoes or socks are a must.

The best time to visit the park is in spring and early summer, when daytime temperatures are mild and Medano Creek flows with cool, refreshing water. Since the park is designated an International Dark Sky Park, the dunes also offer remarkably clear night skies for stargazing.

Before planning your visit, be sure to check the real-time flow of Medano Creek, available from spring through fall, via an online graph that tracks the creek’s volume in cubic feet per second (cfs). While the data is collected about five miles upstream from the main Dunes Parking Area, it offers a useful snapshot of current conditions and whether water levels are rising or falling. This year, flow levels aren’t expected to top 20 cfs, which is a reminder to plan your visit accordingly.

The park is well-equipped for visitors, with dune-rover wheelchairs, convenient dune showers, and the Piñon Flats Campground. Families can participate in a variety of programs, including the National Park Service’s Junior Ranger program and Family Archaeology Days.

For a unique place to stay near the dunes, consider Dunes Desert Camp. This eco-luxury glamping site has just two spacious safari tents, offering a private and immersive experience in nature. Guests can opt for customizable meals and activities through the camp’s Dune Experiences program. For a more traditional stay, Great Sand Dunes Lodge provides a variety of standard room types, as well as campers and geodesic domes.