Anyone who ever slapped up some plywood to build a fort in a backyard tree will bow in awe at the sight of Michael Garnier’s ten designer tree houses scattered around 36 acres of oak and Douglas fir woods adjacent to Siskiyou National Forest in southern Oregon ($110; treehouses.com). Inspired by his own Swiss Family Robinson fantasies, Garnier’s Out ’n’ About Treehouse Treesort has arboreal abodes set as high as 45 feet off the ground. "People usually enjoy a good night’s sleep here," says Garnier. "Unless it’s storming. Then you might have a problem in the taller ones." Overgrown kids get to play on myriad Tarzan swings and ziplines, climb up and rappel down trees, sit around a campfire, head off on horseback rides, or relax in the lodge library filled with books about, yes, tree houses.

To the uninitiated, the wild popularity of the Solvang Century bike ride may come as a surprise (March 14; $65; bikescor.com/solvang). But the country roads near kitschy, Danish-themed Solvang have sundry claims to fame. They link the wineries that seduced the oenophiles in Sideways. They lead to fabled BBQ joints like the Hitching Post. And they’ve served as winter training grounds for Lance Armstrong—proof positive that the two-laners in the Santa Ynez Mountains make for some of the best cycling in the U.S.

Out-of-bounds skiing is something of a foreign concept at Alpine Meadows. The Lake Tahoe resort has an open-boundary policy, which means confident skiers can go where they please, bombing astounding terrain like High Traverse, which traces the Pacific Crest Trail. Not OB ready? Matriculate in Alpine Meadows’ Steep Camps (March 13–15; $658, including lift tickets and lunch; skialpine.com). School director Doug Pierini puts students through a regimen of drills pioneered by the U.S. Ski Team. Mornings include yoga sessions; afternoons, a video analysis of technique. When you’re finished, send the highlight reel along to Warren Miller.

A winter rite of passage has emerged in the wilds of Olympic National Park: snowshoeing up Hurricane Ridge. Twenty miles of trails crisscross the saddle, which hovers above the prevailing rain forest green like a white Xanadu, offering views of Mount Rainier, the Strait of Juan de Fuca, Vancouver Island, and vast old-growth stands below. The six-mile round-trip trudge to the top of Hurricane Hill is the classic way up; it follows a knife-edge route, so you can fancy yourself a climber taking on K2’s Abruzzi Ridge. At the summit, you get a south-facing look at Mount Olympus. Rangers lead easier 90-minute loops on weekends, when Hurricane Ridge Road is also open. Rent snowshoes at Brown’s Outdoor in Port Angeles ($15; brownsoutdoor.com) or for $18 at the Hurricane Ridge Visitor Center, where ranger-led hikes begin.