The storms roll in hard and fast off the Atlantic, hitting the Andes with massive hammer blows of snow, ice and wind. Their power is such that even one week after Liberty Skis has arrived here in Valle Nevado – a veritable island in the sky – there’s still fresh cream coating the mountains. This resort, perched on a ridge so steep you’d think the hotels would slide off it into the abyss, is the ground zero of summer skiing. Other mountains might boast of more luxury (debatable), more “extreme” (also debatable) and more snow (this, too, is debatable), but none can combine the ease of access...