Rocky Mountain National Park, Colorado
There are more than 300 miles of hiking trails in the park, where you could catch glimpses of moose, elk, and blankets of wildflowers. You can choose to camp in the area, or stay at the Stanley Hotel (known for its role as the setting for The Shining).
The Birding: Many nesting birds of the mountain west, like white-tailed ptarmigans and red crossbills, make their homes in these altitudes. Designated as a globally important bird area, birding is decent all year here, but summer is the best time to go.