Denali
Credit: Ron Sanford / Getty Images

Centered around Mt. McKinley, the tallest peak in North America, Alaska's Denali National Park covers six million acres of tundra and forest (larger than the state of Massachusetts) and is known among serious hikers and backpackers for its glaciers and steep cliffs. Expeditions typically take three to four weeks, and most companies require climbers to have experience with high altitudes and heavy backpacks. In summers, a single, 92-mile road meanders throughout the grounds carving out a path for easier sightseeing. It also gets you up close and personal with Alaskan wildlife such as moose, caribou, and grizzly bears. 

Don't Miss: Take the Taiga Trail to the Mount Healy Overlook, a 2.2 mile trek that takes most hikers three to four hours to complete. At the peak, you’ll be able to see the Nenana River Valley and the top of Mt. McKinley 80 miles in the distance.