The Harmony-Preston Valley State Trail runs for 18 miles on a north–south line between the town of Harmony and the Root River State Trail between Lanesboro and Fountain. The paved trail is mostly level, although a section just north of Harmony is relatively steep.
Part of the trail is built upon an old railroad right-of-way; the northern segment follows and crosses Watson Creek, the South Branch of the Root River and Camp Creek, passing through wooded areas and farmland. The southern portion leaves the railroad grade and climbs out of the river bottom to Harmony.
The Harmony-Preston Valley State Trail is popular with cyclists, hikers and inline skaters; cross-county skiing is popular during winter. The trail managers warn users not to leave valuables in their cars while enjoying the trail.
In Preston, take US 52 to Fillmore Street (CR 12) and go about 0.5 mile to the parking lot. In Harmony there are two places to park: take US 52 to 4th Street NW and go about 0.5 mile west to the parking lot. Alternatively, park at the tourist information center at the end of 2nd Street NW just off Main Street.