The “A.T.,” as it's called by hikers, is much more than just a path through the woods. It is a national scenic trail, part of the same national park system that includes Yellowstone, Yosemite, and the Great Smoky Mountains. Its official name is the Appalachian National Scenic Trail. But, unlike those famous parks, it's not a concentrated preserve, with campgrounds and paths within its boundaries. As the longest, skinniest part of America's national park system, the A.T. stretches over 14 different states and passes through more than 60 federal, state, and local parks and forests. Hundreds of roads cross it. In some parts, the Trail “corridor” is only a few hundred feet wide.

Maybe the most important difference between the A.T. and other national-park units, though, is that volunteers make it possible. Each year, thousands of people maintain, patrol, and monitor the footpath and its surrounding lands—outdoor lovers like you volunteering hundreds of thousands of hours of their time to taking care of this public treasure. Learn how you can get involved.

Difficulty Ratings for A.T. Trail Sections

Because the A.T. spans a great variety of terrain, ranging from relatively flat and easy, to extremely arduous, the following scale was created as a general guide:

1=Flat
5=Strenuous ups and downs, only occasional flat sections
10=Use of hands required, footing precarious — not recommended for those with fear of heights and not in good physical condition.

These ratings are listed by state.

Northern New England

Between central Maine and western New Hampshire, this section offers some of the most rugged hiking and most challenging weather conditions of the entire A.T. The path is often steep, rough and slippery. Parts are above treeline, where weather is especially severe. It includes Katahdin, the Trail's northern terminus in Maine, the wild country of the “Hundred Miles,” the Mahoosuc Range, and the White Mountains. Explore: Maine, New Hampshire.

Southern New England

Between eastern Vermont and the New York-Connecticut border, much of this section runs along glacier-scraped mountain ridges such as the Green Mountains and the Berkshires, and rocky New England river valleys. Though less strenuous than the northern section, it offers a challenging hike through deep forests, yet lies within easy driving distance of major cities such as Boston and New York City. Explore: Vermont, Massachusetts, Connecticut.

Mid-Atlantic

Between eastern New York and central Maryland, this section of the A.T. runs between the glacial hills of the Hudson Highlands, and the northern reaches of the Blue Ridge Mountains. It follows long, rocky ridges only a few thousand feet above sea level—ridges that often seem like islands of wild country above bustling valleys. Hiking is mostly moderate, but parts can be very rocky and strenuous. Explore: New York, New Jersey, Pennsylvania, Maryland.

The Virginias

Between the eastern panhandle of West Virginia and the Tennessee border, the Trail runs along the Blue Ridge of Virginia and the Great Valley of the Appalachians. This section includes portions of Harpers Ferry National Historical Park, Shenandoah National Park, and the Blue Ridge Parkway. Hiking is moderate to strenuous, and the southern part offers long, solitary stretches. Explore: West Virginia, Virginia.

Southern Appalachians

The Trail runs between northeastern Tennessee and the southern terminus at Springer Mountain in Georgia. It penetrates several of the vast national forests of the South, and crosses the Trail's highest mountain, Clingman's Dome, in the Great Smoky Mountains National Park. Though mostly well-graded, the Trail through this section is remote, with long, strenuous climbs. The high ridges along the North Carolina-Tennessee border are prone to winter weather similar to parts of New England. Explore: Tennessee, North Carolina, Georgia.