Ohio State Route 503 is the main north-south highway in Eastern Preble County. OH St Rt 503 passes through the following towns in Preble County. West Elkton Gratis West Alexandrie Lewisburg West Sonora OH St Rt 503 is multi-plexed in Preble County. Ohio State Route 122, at Gratis. OH St Rt 503 intersects the following highways in Preble County. Ohio State Route 122, at Gratis. Ohio State Route 122, at Gratis. Ohio State Route 725, at Gratis. U.S. Rt. 35, at West Alxendria. Interstate 70, at Lewisburg. U.S. Rt. 40, at Lewisburg.
