I steadied myself with outstretched arms against the rock face in front of me and eased out onto the unstable ridge. If I made it, this barren stretch of boulders would funnel me into one of Stowe Mountain Resort’s best unmarked glades. But one wrong twitch on this rocky cliff and I could tumble down a 30-foot embankment with nothing to look forward to but a vast ocean of ice and jagged granite.