BEST: SEPTEMBER–OCTOBER, WHEN THE SAND IS COOL

The last thing you expect to see next to 14,000-foot peaks is a 30-square-mile chunk of Sahara-like desert. The unlikely juxtaposition makes Great Sand Dunes National Park and its surrounding 65-square-mile mountain preserve one of the most remarkable spots in the country. The dunes are the main draw—griddle hot in the summer, they're cool enough by fall to justify the four-hour drive from Denver or Albuquerque. But the best way to view them is from above. The 4x4-only Medano Pass road accesses the trailhead for the eight-hour round-trip hike to 13,353-foot Mount Herard, which offers an incredible high-alpine view of the dune field. And the easy Sand Ramp Trail, which skirts the eastern edge of the dunes, connects the only creekside backcountry campsites (permits are free but first-come-first-served; nps.gov/grsa). Afterwards, head 35 miles southwest to Alamosa, where you can rehydrate at the San Luis Valley Brewing Company (slvbrew­co.com).