The National Trails System includes over a thousand trails throughout the United States, and is administered by the federal government.

Most of the National Scenic Trails and National Historic Trails are fairly long, and most visitors hike only a portion of the trail, or may take several years to finish, tackling it for a few days at a time. The trails may cover a combination of federal, state, and local land, and may go through private lands as well.

National Scenic Trails, National Historic Trails, and National Geologic Trails are designated by act of Congress, marking them among the best trails of the nation.

National Scenic Trails

National Scenic Trails have been established in order to allow public access through areas of "spectacular natural beauty and to allow the pursuit of healthy outdoor recreation." There are eleven of these trails. The most popular is the Appalachian Trail running from Georgia to Maine. American hiking enthusiasts have labeled three of these—the Appalachian, Continental Divide, and Pacific Crest National Scenic Trails—the "Triple Crown" of hiking conquests.

• Appalachian National Scenic Trail — 2175 miles (3500 km), a Canadian trail continues 690 miles (1100 km) into New Brunswick & Quebec. It is being extended a further 1200 km along the west coast of the island of Newfoundland.
• Arizona National Scenic Trail — 807 miles (1309 km)
• Continental Divide National Scenic Trail — 3100 miles (4990 km)
• Florida National Scenic Trail—1300 miles ( km)
• Ice Age Trail — 1000 miles (1600 km)
• Natchez Trace National Scenic Trail — 695 miles (1120 km)
• New England National Scenic Trail — 220 miles (370 km); was recognized as a NST (National Scenic Trail) in March 2009
• North Country National Scenic Trail — 3200 miles (5150 km)
• Pacific Crest National Scenic Trail — 2638 miles (4245 km)
• Pacific Northwest National Scenic Trail — 1200 miles (1520 km); was recognized as a NST (National Scenic Trail) in March 2009
• Potomac Heritage National Scenic Trail — 700 miles (1120 km)

National Historic Trails

Following historic routes or themes, the National Historic Trails emphasize the history of the areas covered. They tend to be less demanding than the Scenic Trails. Some people follow these trails by car or bus, stopping at many of the same sites as hikers, but getting to some of the more remote historic gems requires hiking in.

Most of these trails have trail markers along the route, brochures and documentation leading you through the trail, and many enthusiastic supporters online who can help you make the most of your trip.

• Ala Kahakai National Historic Trail—175 miles
• California National Historic Trail—5665 miles
• Captain John Smith Chesapeake National Historic Trail—3000 miles
• El Camino Real de los Tejas National Historic Trail—2580 miles
• El Camino Real de Tierra Adentro National Historic Trail—404 miles, US segment of the 1600-mile Mexico City-Santa Fe hiking trail following a colonial trade route.
• Iditarod National Historic Trail—2350 miles
• Juan Bautista de Anza National Historic Trail—1200 miles
• Lewis and Clark National Historic Trail—3700 miles
• Mormon Pioneer National Historic Trail—1300 miles
• Nez Perce National Historic Trail—1170 miles
• Old Spanish National Historic Trail—2700 miles
• Oregon National Historic Trail—2170 miles
• Overmountain Victory National Historic Trail—275 miles
• Pony Express National Historic Trail—1966 miles
• Santa Fe National Historic Trail—1203 miles
• Selma To Montgomery National Historic Trail—54 miles
• Star-Spangled Banner National Historic Trail—290 miles
• Trail Of Tears National Historic Trail—2200 miles
• Washington-Rochambeau Revolutionary Route National Historic Trail—in 2010, the route for this new trail was under development

National Geologic Trail

The first National Geologic Trail was created by the 2009 stimulus package and further development was planned.

• Ice Age Floods National Geologic Trail

National Recreation Trails

There are over a thousand National Recreation Trails, spread across every state. These trails are designated by the Secretary of Agriculture or the Secretary of the Interior, and are generally managed by non-profit groups or state or local government. You will probably find several of these trails within an easy day's travel from most cities in the U.S.

National Recreation Trails may be less than a mile long, or may be over a thousand miles. They may be tailored to various types of activities, such as archery, skeet shooting, dog mushing, mountain biking, horse riding, inline skating, cross-country skiing, kayaking, or simple hiking. Some are ADA-accessible.

A list of all National Recreation Trails is available here.