The Great Smoky Mountains National Park
Reputed to have the largest number of old growth trees in the eastern United States along with some of the tallest peaks east of the Rocky Mountains, the fall months will find the park ablaze with the colors of autumn. According to Fodor's, the park is considered a United Nations International Biosphere Reserve and World Heritage site because of its numerous species of trees and birds. In addition, wildlife from bear to salamanders is abundant. Located on the border of Tennessee and North Carolina, those who enjoy hiking will be able to follow the Appalachian Trail through the park along the mountain crests, and there are several other trails for those who would prefer lower elevations. If fishing is your thing, there are 600 miles of trout streams. If time doesn't permit lengthy activities, the park can still be enjoyed by taking advantage of the numerous roadside turnouts in its 800 square miles.
Great Sand Dunes National Park
While a desert might not seem the best destination any time of year, those who travel to Colorado's Great Sand Dunes National Park will be richly rewarded. Aptly named for its towering sand dunes, the park also boasts a diversity of life that's hard to find anywhere else. While the shifting dunes may attract the most attention, the park also includes lush forest growth, wetlands and tall mountain peaks. There is also plenty of wildlife including pronghorn antelope, bighorn sheep, deer and a large herd of bison. Vegetation varies from the prickly pear cactus of the desert region to the pine and fir trees in the mountain area. Dune climbing and hiking are among the most popular activities with some trails offering a change of 2,000 feet in elevation over their course.
Acadia National Park
The oldest national park east of the Mississippi, Acadia National Park offers a breathtaking view of the Maine coastline as well as containing mountain vistas and spectacular fall foliage. The park also comes complete with a lighthouse and plenty of trails for biking and hiking, as well as numerous chances for fishing, boating and camping. When it comes to wildlife, there are lots of "watching" opportunities from bird to whale.
Yellowstone National Park
It's hard to beat Yellowstone when it comes to the best parks to visit during the fall. Yellow, gold, red and orange foliage often contrasts with the greens of fir and pine trees and bright blue skies. The steam from erupting geysers gives an almost ethereal quality to the landscape as herds of elk, deer, moose and bison begin to migrate across the vast acreage, often followed by wolves. Visitors can sometimes catch glimpses of black bears and the occasional grizzly. Ducks, geese and swans can often be seen as they pass overhead. The park offers plenty of chances for hiking and fishing, and there are several locations that provide camping for longer stays. One trip to Yellowstone and it's easy to see why this became the nation's first national park.