Delicate frost clings to a solitary tree at J. Clark Salyer National Wildlife Refuge in North Dakota. These little details are easy to miss when visitors are busy bird watching, hiking or ice fishing. Extending from the Canadian border for 45 miles, it’s the largest wildlife refuge in the state and one of the nation’s premier birding locations. Photo by Colette Guariglia, U.S. Fish and Wildlife Service.
Winter has Tetlin National Wildlife Refuge in its icy grip. For countless generations, the Upper Tanana Valley of Alaska has served as a natural travel corridor – for wildlife, native people and explorers. Despite the blanket of snow, many animals live here year round – including the Great Grey Owl, which preys on small rodents. Photo by U.S. Fish and Wildlife Service.
Take a walk through a winter wonderland at Yellowstone National Park. While it looks a light coating of snow at Tangled Creek, the landscape is covered in hoar frost, which forms when water vapor freezes quickly creating delicate, feather-like crystals. Photo by Jacob W. Frank, National Park Service.