Winter wonderlands come in many shapes, forms, and temperatures in the National Park System. They can be pine forests shrouded in snow, or turquoise waters swimming with green parrotfish, blue tangs, and silvery barracudas. You can climb ice walls at Acadia National Park, kick-and-glide or skate to an overlook of Half Dome and the Yosemite Valley, or find your way to the 13,159-foot summit of Wheeler Peak atop Great Basin National Park.