In winter Rocky Mountain National Park becomes a different place entirely. The crowds disappear, the high country goes white, and the wildlife that summers above treeline moves down into the valleys. Elk gather in large herds on the snow-covered meadows near Estes Park. Bighorn sheep pick their way across wind-scoured ridges. The tundra above 11,000 feet is locked in ice and silence. Trail Ridge Road — the highest continuous paved road in the United States at 12,183 feet — closes to vehicles but the park stays open. Winter light on fresh snow at altitude is unlike anything at lower elevations.