It's a little-known fact that the blue "smoke" for which the Great Smoky Mountains are named is less a meteorological phenomenon than a biological one. The culprit is plant respiration on a massive scale, emanating from mountains whose biodiversity is practically Amazonian. Wildflower blooms rival those of the Rockies and the Sierra. Rhododendrons climb to tangles 20 feet high. And groves of virgin deciduous forest give the impression of a continent lost to time. At the region's heart is Great Smoky Mountains National Park, the Appalachians concentrated and magnified.

GAME PLAN: Escape the park's notorious crowds on a four-day backpack that begins on the mellow Big Creek Trail in Great Smoky's northeast corner. Just 1.4 miles in, you'll hit the Midnight Hole, a paradisiacal plunge of dark blue-green water that demands a brisk swim. Dry off and proceed another four miles to Campsite 37. On day two, pick up the Gunter Fork Trail and start the steep six-mile hike up to Laurel Gap Shelter on the flanks of Balsam Mountain. Day three drops eight densely wooded miles to Campsite 39 by way of the Balsam Mountain and Palmer Creek Trails. On the final day, start early for the nine-mile hike out through Cataloochee Valley—you'll see reintroduced elk grazing in meadows as you pass by remnants of historic Appalachia like the Beech Grove School and Palmer Chapel. Climb out of the valley on the Big Fork Ridge Trail then the Hemphill Bald Trail. You'll end up at the Swag hotel, the ultimate place to drop your bag, grab a meal or a bed, and celebrate what you've just accomplished.

Vitals: All overnight hikes require backcountry permits; Campsite 37 and Laurel Gap Shelter require reservations (free; 865-436-1231). For car shuttle service, check with A Walk in the Woods (prices vary by trip; awalkinthewoods.com).

The Must-Do: The 5.5 miles to Mount Cammerer Lookout from Cosby Campground take in old-growth forests and one of the park's best views, ridgelines north into Tennessee.

Base Camp: Haute rustic is an apt description of the Swag, a luxury inn at the edge of Great Smoky. Bearskins hang above a huge stone fireplace. Adirondack chairs are placed to maximize views. And the food is new southern. Example: crab and wild mushroom cheesecake (doubles from $490, including meals; theswag.com)

BONUS QUIZ: Think you know Great Smoky Mountains National Park? Test yourself with this quiz.