This seven-mile long trail is a paved path that parallels Four Mile Run, extending from Falls Church to the Mount Vernon Trail
near the airport when the trail dead ends at the Mount Vernon Trail
and Four Mile Run pours into the Potomac River. The trail runs roughly parallel to parts of the Washington & Old Dominion Railroad Trail along its length, although runners will sometimes be on the other side of the creek. There are some hills along the way but when taken from west to east, the trail is mostly downhill.