Great Sand Dunes National Park

Great Sand Dunes contains the tallest sand dunes in North America (Star Dune and Hidden Dune both top 750 ft of relief from the Medano Creek floodplain) set against the Sangre de Cristo Mountains in southern Colorado. The dunes formed when prevailing southwesterly winds funneled sand into a natural pocket against the mountains, where it has accumulated for at least 440,000 years. Spring snowmelt creates Medano Creek, a wide, shallow stream that flows along the dunes' east edge from late April through early July with surge waves, a phenomenon found in only a handful of places worldwide. From I-25 the standard access is Exit 52 in Walsenburg, then 75 mi west on US-160 over La Veta Pass to the San Luis Valley, then north on CO-150 to the entrance. The park was redesignated from monument to national park (and preserve) in 2004.

• Tallest dunes in North America, Star Dune at ~750 ft of relief
• Medano Creek flows beside the dunes April to July with rare surge-wave phenomenon
• Park designated 2004 (formerly a national monument since 1932)
• Dune sand surface temperatures can exceed 150°F on summer afternoons
• San Luis Valley around the park is one of the largest alpine valleys in the world

• Hike to High Dune (650 ft, ~2 hours)
• Medano Creek splash and surge waves (April to July)
• Dune sledding and sandboarding (rentals in nearby Mosca)
• Mosca Pass Trail into the Sangre de Cristos
• Zapata Falls (BLM land just south of the park)

Best months: May through June for Medano Creek and cooler dune surface temps; September to October for clear skies and minimal crowds.

Closures: No seasonal road closures on the main paved network. Medano Pass Primitive Road is closed October through May. Visitor center and main dunes parking stay open year-round.

Notes: Summer dune surface temperatures exceed 150°F by mid-day, wear closed-toe shoes and avoid midday climbs. Lightning is a serious hazard on the dunes during summer afternoons.