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).