The American Discovery Trail stretches 4900 miles across the USA, from Point Reyes National Seashore on the Pacific in California to Cape Henlopen State Park on the Atlantic in Delaware.  In the mid-section of the country, between Colorado and Ohio, there are 2 branches of the trail - north and south.

The ADT Website describes it as follows:

Jakub Sliacan submitted the route:

Mailbox Peak (4822') is a very popular hike near North Bend, WA.

Bryan Blake submitted the route:

A 100K (62 mile) single-loop road route encompassing all 50 US state-named streets within Washington, DC. Link to route map is here:

http://www.mapmyrun.com/us/washington-d-c-dc/50statesdc-course-1441792