U.S. Federal Route 20A runs east-west in East-Central Williams County. It runs from the Williams/Fulton County Line, near West Unity, to U.S. Rt. 20 near Pioneer. U.S. Rt. 20A passes through the following towns in Williams County. West Unity Montpelier Holiday City U.S. Rt. 20A is multi-plexed in Williams County. U.S. Rt. 127, at West Unity. Ohio State Route 15, from Montpelier to near Pioneer.