Katmai National Park & Preserve in Alaska provides some of the few remaining unaltered habitats for bears. With about 2,200 brown bears in the park, scientists are able to study bears in their natural habitat, visitors are able to enjoy unparalleled viewing opportunities (from safe distances) and the bears are able to continue their life cycle largely undisturbed. Photo by Mike Clime (http://ift.tt/18oFfjl).

Rising nearly 5,000 feet above Yosemite Valley and 8,800 feet above sea level, Half Dome is a Yosemite National Park icon and a great challenge to many hikers. At least a 14-mile round trip through wilderness with an elevation gain of over 4,800 feet, this hike is not for the unprepared. Permits are required to reduce crowding – protect natural and cultural resources, and improve safety. But for those who make to the top, the view is indescribable. Photo by National Park Service.

Assateague Island National Seashore protects sandy beaches, salt marshes, maritime forests and coastal bays along a strip of barrier island that stretches across the Maryland and Virginia border. In this dynamic coastal environment, the island is continuously being reshaped by wind and water. Explore life on the edge of the sea by crabbing, clamming, kayaking, biking and camping – be sure to plan ahead, as campsites for the summer start filling up in March! Sunrise photo by Jake Breach (http://ift.tt/18oFfjl).

The waters of Leigh Lake at Grand Teton National Park in Wyoming reflect the deep green of the surrounding trees. Photographer Dennis Liew enjoyed this perfect moment with his girlfriend. “We canoed to the eastern side to watch the sun light up the mountains. It was a serene moment; the air was calm and not a soul there disturbed the peace.” Photo courtesy of Dennis Liew.