Washington’s Methow Valley is the literal end of the road in winter. There’s one way in from the south. There’s route 20, a sinuous side spur plunging down from Omak in the Okanogan Highlands to the Methow’s eastern edge. Otherwise, travel by car terminates just beyond Mazama — the small town nestled in the valley’s north. The Methow’s charm remains its solitude and mellowed pace. Despite the wifi and cell service, there’s the real...