Ohio State Route 66 runs north-south in west-central and northwestern Ohio. The route begins in Piqua, and it runs north to almost reach the Michigan state line. The southern beginning of Ohio Route 66 occurs at US Route 36 in downtown Piqua. From there, Ohio Route 66 runs northwest to Newport, where it crosses Ohio Route 47 and turns northerly for the rest of its path. That northerly path meets a lot of small towns, like Fort Loramie, Minster, New Bremen, and Saint Marys. Beyond Saint Marys, Ohio Route 66 passes through Delphos, Defiance, and Archbold. North of Archbold, Ohio Route 66 ends at Ohio Route 120 in Fayette. Most traffic reaching the northern end of Ohio Route 66 will jog westerly along Ohio Route 120 for a mile and a half, to turn northerly onto US Route 127.