Home to North America's tallest sand dunes rising 750 feet above the San Luis Valley floor, with the dramatic Sangre de Cristo Mountains as a backdrop. The unique landscape includes a seasonal creek, conifer forests, and alpine lakes just beyond the dunes.
Great Sand Dunes National Park and Preserve, located in the San Luis Valley of south-central Colorado near the town of Mosca, protects North America's tallest sand dunes alongside a surrounding mosaic of wetlands, grasslands, conifer forests, and alpine tundra. The dunes field covers 30 square miles and rises to 750 feet above the valley floor, backed by the Sangre de Cristo Mountains reaching over 14,000 feet — a dramatic pairing of desert and alpine landscapes found nowhere else on the continent.
The dunes formed through a geologically complex process spanning tens of thousands of years. Streams flowing off the Sangre de Cristo Mountains carried sand westward into the San Luis Valley, where prevailing southwest winds transported the sand northeast toward the mountains. Medano Creek and Sand Creek, flowing at the edge of the dunes field, act as a sand recycling system — catching sand that blows over the dunes and returning it to the dunefield, creating a self-contained ecosystem in dynamic equilibrium.
Medano Creek flows across the base of the dunes seasonally, typically from late April through July. The creek's unique surge flow — caused by subsurface sand releasing water in pulses — creates a shallow, wave-like stream visitors can wade through. For families with children, Medano Creek in May and June functions as a natural water park at the edge of an otherworldly landscape.
The dunes are accessed via an unmarked, open hiking area with no established trails — visitors walk from the Dunes Parking Area across Medano Creek and up whatever dunes they choose. High Dune at approximately 699 feet and Star Dune at 750 feet are the commonly reached summits, achievable via 2- to 4-hour round trips depending on pace. The sand surface is physically demanding; every step on loose slopes requires significant effort, and sand temperatures can exceed 150°F on the surface in summer, making footwear essential. Early morning hiking is strongly recommended in July and August.
Beyond the dunes, the preserve encompasses the Sangre de Cristo Wilderness, accessible via backcountry trails to alpine lakes including Upper and Lower Sand Creek Lakes above 11,000 feet. The park's remote location in the San Luis Valley, one of the darkest areas in Colorado, makes it one of the state's finest stargazing destinations, with a certified International Dark Sky Park designation.
Good to know
- Hours
- Park open year-round; Visitor Center 9AM-4:30PM
- Best time
- Sunrise or late afternoon
- Best for
- families, adventure seekers, photographers, stargazers
Location
11999 CO-150, Mosca, CO 81146
37.7916, -105.5943 View on map
Highlights
- North America's tallest sand dunes rising 750 feet with the 14,000-foot Sangre de Cristo Mountains as backdrop
- Medano Creek surge flow — a shallow, wave-like seasonal stream running across the dune base from April through July
- Open dune hiking with no trails — visitors choose their own route across 30 square miles of dune terrain
- International Dark Sky Park designation with some of Colorado's darkest skies for stargazing
- Sangre de Cristo Wilderness alpine lakes accessible by backcountry trail above 11,000 feet
Tips for visiting
- Bring sand sleds for the dunes - rentable at the park entrance
- Medano Creek is seasonal (May-June) and perfect for wading
- Sand temperatures can exceed 150°F in summer - go early morning or evening
When to visit
Late May and early June offer the ideal combination of flowing Medano Creek for wading, cooler sand temperatures for hiking, and long days. Sunrise and the two hours after are the best times on summer days before sand surface temperatures become extreme. Late September through October brings pleasant hiking temperatures with no creek but dramatically smaller crowds.
Accessibility
The Visitor Center and Dunes Parking Area are accessible. A paved accessible path leads from the parking area toward Medano Creek, though the creek crossing and dune surface itself involve loose sand not suitable for wheelchairs. Sand wheelchairs are available for loan from the visitor center on a first-come basis, allowing some mobility-impaired visitors to access the dune base area.
Frequently asked questions
How long does it take to hike to High Dune or Star Dune?
High Dune (699 feet) takes approximately 1.5 to 2.5 hours round trip from the parking area, depending on pace and sand conditions. Star Dune, the tallest at 750 feet, is 3.5 to 4 miles round trip and typically takes 3 to 4 hours. Sand hiking is significantly more physically demanding than equivalent distances on solid trail.
When is Medano Creek flowing?
Medano Creek typically flows from late April through early July, with peak surge flow in May and June following snowmelt from the Sangre de Cristo peaks. By late July the creek often dries to a trickle or stops entirely. The National Park Service posts current conditions on the park's website.
Is it safe to take children onto the dunes?
Yes — children generally love the dunes, particularly the Medano Creek wading area at the base. Families should plan dune hikes for early morning in summer when sand temperatures are manageable. Carry plenty of water, apply sunscreen, and bring extra footwear as sand gets inside shoes quickly.