From Vaughnsville, SR 12 travels northeast through the small towns of Columbus Grove, Pandora, and Benton Ridge before entering Findlay.

Through Findlay, it shortly shares a route with US 224.

After exiting Findlay, it continues on a northeast heading, passing through Arcadia, Fostoria, and Bettsville before ending at SR 53.

The 7.2-mile-long (11.6 km) truck route begins at State Route 12's interchange with Interstate 75 on the west side of Findlay.

It then moves south along Bright Road to reconnect with SR 12 on the east side of Findlay.