The forested wetlands of Pocosin Lakes National Wildlife Refuge in North Carolina provide excellent habitat for migratory birds. Large numbers of waterfowl concentrate on this relatively small area in the winter with peak numbers of well over 100,000 gathering in December and January. It is also home to the only population of wild, free roaming red wolves in the world and supports several clusters of endangered red cockaded woodpeckers. Here, a large flock of tundra swans fly over the refuge at sunset. Photo by Ginny P. Gillam (http://ift.tt/18oFfjl).

On this day in 1915, Rocky Mountain National Park in Colorado officially became a national park. Even in cold weather, you can explore the park’s spectacular mountain environments by snowshoeing, cross-country skiing, sledding and wildlife watching. In fact, winter is an especially good time to look for elk, mule deer, moose and other large mammals. Sunrise photo of Dream Lake in 2014 by C. Brindle, National Park Service.

One of nature’s most social and playful creatures, river otters have big personalities and even bigger appetites. Often seen in groups, they can be observed hunting and frolicking year round at Loess Bluffs National Wildlife Refuge in Missouri. In winter, you might even catch them sliding across the ice on their bellies. Photo courtesy of Kenny Bahr.

Wide expanses of land make Southwest sunsets some of the best in the United States, and the view from Glen Canyon National Recreation Area is no exception. Straddling the border of Utah and Arizona, this desert gem is a perfect place to explore golden cliffs, lush hanging gardens, narrow slot canyons and the brilliant blue paradox of Lake Powell. Photo by Jeremy Stevens (http://ift.tt/18oFfjl).

Icy water reflects the sunset at Edwin B. Forsythe National Wildlife Refuge in New Jersey. More than 80 percent of the refuge’s 47,000 acres is wetlands. The quiet tidal waters serve as nurseries, spawning and feeding grounds for fish and shellfish, which are important in the diets of many wildlife species – particularly the migratory birds who live and visit here. Photo by Kris Orr (http://ift.tt/18oFfjl).

From snow-blanketed mountains to evergreen forests dripping with rain to ocean beaches pounded by winter storms waves, there are many ways to experience winter in Olympic National Park in Washington. Hurricane Ridge is the epicenter for snow and winter recreation, with opportunities for snowshoeing, cross-country and downhill skiing, snowboarding and tubing. Be sure to check conditions before you go, as heavy snows can lead to road closures. Photo by John Robinson (http://ift.tt/18oFfjl).

While Acadia National Park in Maine is famous for its sunrises, stay after dark to view incredible night skies and experience Acadia’s rocky coastline by starlight. Dark night skies are great for stargazing and serve as a crucial resource for nocturnal plants and animals. Photo of the Milky Way over Boulder Beach courtesy of Manish Mamtani.

At the west end of the National Mall in Washington, D.C., the Lincoln Memorial stands in tribute to President Abraham Lincoln. It’s not only a reminder of one of our history’s greatest figures, but a place of celebration, education and demonstration. In times of trouble and of peace, the National Mall has served as America’s symbolic front yard and the eyes of Lincoln’s statue have kept watch over our unfolding history. Photo by Yu Sheng (http://ift.tt/18oFfjl).

Zion National Park’s reddish rocks wear a coat of snow in this serene winter photo from last January. After winter storms, snow can disappear within just a few hours at lower elevations, making these magical sights short-lived. If you’re visiting, be sure to check with the park for the most recent conditions and closures. Photo by Sierra Coon, National Park Service.

We can’t help but smile after seeing this big grin from one of the fishes at Florida Keys National Wildlife Refuge Complex. Comprised of four refuges situated in the Florida Keys, the complex protects the critical habitats on the land and in the water for wildlife like the American crocodile, the endangered Key deer, the Great White Herons and others. Photo by Kristie Killam, USFWS.