Great Sand Dunes NP Guide: Tall Dunes, Alpine Lakes & Wilderness
Great Sand Dunes National Park & Preserve
“Where towering sand dunes meet high mountains, clear alpine lakes, and night skies so dark the stars feel close.”
Park Overview
Great Sand Dunes National Park & Preserve in south-central Colorado protects over 149,000 acres of dunes, sand sheets, wetlands, alpine lakes, and forested mountains. The park preserves the tallest dunes in North America—some reaching 750 feet high—set against the Sangre de Cristo Range. What began in 1932 as a national monument was expanded and redesignated as a national park & preserve in 2004.
Fast Facts
| Location | Alamosa & Saguache Counties, Colorado |
| Established | Monument in 1932; Park & Preserve status 2004 |
| Total Area | ≈ 149,028 acres |
| Dune Field Size | ~30 square miles |
| Max Dune Height | ~750 ft (Star Dune) |
| Elevation Range | ~7,500 ft in valley up to >13,600 ft (Tijeras Peak in Preserve) |
| Annual Visitors (pre-pandemic) | ~527,000 (2019) |
What to See & Do
- Climb the Dunes – Hike out across sand, feeling surface temperatures in summer that can exceed 150°F; sunrise and sunset are cooler and gorgeous.
- Medano Creek – Seasonal stream with “surge” flows in late spring/early summer; in wetter months, shallow water trickles around dune bases and creates fun interactions with the sand.
- 4WD & Backcountry Roads – Medano Pass Road for four-wheel drive access; scenic drives and access to alpine lakes in the preserve.
- Forest & Alpine Lakes Trails – Hike up from the valley to forested zones and alpine lakes in the Sangre de Cristo Range.
- Stargazing – Dark skies, remote setting; great opportunity for night photography and astronomy.
Geology & Natural History
Geologically, the dunes formed as sediments washed down from the high mountains filled ancient valleys (including Lake Alamosa) that later dried. Winds and creek flows recycle sand, creating and reshaping the dunes. Several ecosystem zones—from wetlands and grasslands at valley floor to forest, montane, and alpine tundra at higher elevations—coexist here.
Wildlife & Ecology
The park preserves diverse life. Over 250 bird species; mammals like mule deer, black bears, cougar; alpine species like pika and yellow-bellied marmots; reptiles in warmer zones; and many endemic insects adapted to dunes and sabkha areas. Plant life ranges from cottonwoods and aspens near wet areas to bristlecone pines in higher elevations.
Human History & Culture
Humans have lived in the San Luis Valley for over 11,000 years, including ancestors of the Southern Ute, Apache, and Navajo peoples. The dunes were first protected as a national monument in 1932 to prevent mining and concrete plant threats. Later expansion included areas of alpine preserve.