Its western terminus is at the Indiana state line 4 miles (6.4 km) west of Payne (the route once continued west in Indiana as State Road 14), and its eastern terminus is at US 23 in Fostoria.

From the Indiana state line, State Route 613 follows a generally easterly direction through small towns such as Payne, Oakwood, and Continental.

It continues in an eastern direction, drifting north, through Van Buren, until it meets State Route 18 south of Bloomdale.

State Route 613 and State Route 18 run concurrently for 10 miles (16 km), heading into Fostoria.

[1][4] In 2012, the City of Fostoria and ODOT proposed removing this segment of SR 613 from the state highway system due to the narrow streets with the aim of reducing truck traffic through the city.