The mountains around Methow Valley [1] are becoming increasingly popular with rock climbers. Mazama Mountaineering (42 Lost River Rd., Mazama, 509/996-3802) teaches one- to seven-day classes and guides rock climbing, backcountry skiing, snowboarding, and mountain biking trips.
Winthrop Mountain Sports (509/996-2886 or 800/719-3826, www.winthropmountainsports.com [2]) rents bikes, skis, backpacks, snowshoes, and sleeping bags.
Links:
[1] http://www.moon.com/destinations/washington/north-cascades/methow-valley
[2] http://www.winthropmountainsports.com