Ohio State Route 603
State Route 603 is a north-south state highway in the northern portion of the U.S. state of Ohio. Its southern terminus is at State [Route 95 |State Route 95] near Perrysville, and its northern terminus is at State [Route 61 |State Routes 61] and Ohio [State Route 98|98] in Plymouth along the Baseline Road that separates Huron [County, Ohio|Huron County] and Richland County, and subsequently the southern boundary of the Firelands and Connecticut [Western Reserve].