ROCKIESWinter-Cast for Trout, Colorado
No self-respecting fly fisherman lets a little thing like winter get in the way of tossing a nymph into a mountain stream. The fishing guides at the Lodge at Vail understand -- and encourage -- such obsessiveness with their Reel Winter trip ($1,797 for two; www.lodgeatvail.com), a three-day fly-fishing trip that includes lodging, gourmand-worthy meals and a half day of guided fishing on the free-flowing, trout-stuffed Eagle River. For an emergency post-fishing warm-up, crack open the house-provided bottle of single-malt Scotch.
Escape Las Vegas, Nevada
Just a half hour from Sin City is singletrack central: Red Rock Canyon National Conservation Area is laced with folds of flaming ocher sandstone and more than a hundred miles of smooth-sailing desert trails at all levels of challenge. Make a weekend of it by teaming up with Escape Adventures ($390; www.escapeadventures.com), which houses riders at the historic Bonnie Springs Ranch, the only hostelry in the preserve, and guides them along the 15-mile (24-kilometer) Old Spanish Trail, a precipitous path hugging the base of a 2,000-foot-high (610-meter-high) red-rock fault line.
Ski the High Uintas, Utah
The backcountry section of Utah's 1.2-million-acre (485,623-hectare) Wasatch-Cache National Forest is so resolutely vehicle-free that forest service employees had to airlift in the area's newest yurt. Boundary Creek Yurt ($50; +1 307 789 1770) is one of five huts set high on the slopes of the Uinta Mountains two hours north of Salt Lake City. Skiing distances between the woodstove-heated yurts range from two to six miles (three to 10 kilometers), and the trail, which penetrates thick lodgepole pine and Engleman spruce forests, rarely dips below 8,000 feet (2,438 meters).
Mush the Boundary Waters, Minnesota
The mushing mavens at White Wilderness Sled Dog Adventures in Ely, Minnesota, urge aspiring dog drivers to "gee" and "haw" their own well-trained team of six huskies ($895 for four nights; www.whitewilderness.com); no sitting back and letting a guide do the work. Mushers are based at a yurt on remote, inappropriately named August Lake in boreal Superior National Forest and the Boundary Waters Wilderness Canoe Area, where they spend days plying the conifer-covered hills and nights ogling the unsullied skies and northern lights.
Paddle a Lone Star Trail, Texas
Dialed-in Texas kayakers don't just sightsee on the Lighthouse Lakes Paddling Trail near Aransas Pass. They fish. The trail is a series of loops ranging from 1.25 to 6.8 miles (two to 11 kilometers) amid 700 acres (283 hectares) of black mangrove trees. "The water is so clear and shallow that you can see oyster shells, sea grass, and the tails of redfish rooting around for food," says Jennifer Thomas, co-owner of Slowride Guide Services and Kayak Rentals , in Aransas Pass ($55 a day for kayak rental; www.slowrideguide.com).
Crawl Into an Ice Cave, Wisconsin
Ice doesn't get any cooler than in the sea caves of Apostle Islands National Lakeshore, in northern Wisconsin. "Icy curtains cover red sandstone walls, and icicles shoot out at odd angles from the cave roofs," says park chief Neil Hauk. Some grottoes are huge; others are duckwalk only. The one prerequisite: Lake Superior must be frozen enough for you to walk or ski offshore; call the Apostle Islands Ice Line (+1 715 779 3397) for conditions. At night, dig into the five-course feast ($49; www.rittenhouseinn.com) at Old Rittenhouse Inn , in Bayfield.