Imagine a living-history museum of Sixties skiing run by Yankee curmudgeons from the local health-food store, and you've got the wonder that is Mad River. This mountain has minimal snowmaking or grooming, a single chair that drips grease (but only on warm days) and perhaps the best, toughest, bargain-priced skiing in the East. Add ownership by its 1,600 anti-glitz co-op members, who dress down in Carharts, ponytails and free-heel skis, and you've got what one reader called "a true skier's paradise." As always, it's not for everyone. Because it doesn't make much snow, Mad River is more easily victimized by the vicissitudes of Eastern weather. As one reader quips, "If you don't start the day with rock skis, you will finish it with them." The ungroomed slopes can mean moguls the size of mobile homes on even the easier runs, and the single chair moves people uphill about as fast as a bicycle would. Which is exactly how the devotees of Mad River like it. The low-capacity lifts mean uncrowded descents down all 45 trails, from narrow, old-style winders such as Paradise and Antelope to brutal, bump-laden verticals such as Chute and Liftline. Since the entire 800 acres are officially inbounds, locals have a hundred secret tree runs, some of them not more than 10 feet wide. As a result, the fans of Mad River are truly rabid: The worst thing they can imagine, one of them writes, is that Mad River Glen "might change or improve."