Illinois State Route 251 is the main north-south surface route through Winnebago County, east of the Rock River. This highway connects the north and south sides of the Rockford-Metro to Downtown Rockford. IL St Rt 251 passes through the following towns in Winnebago County. Rockford
Loves Park Machesney Park Roscoe IL St Rt 251 is not multi-plexed in Winnebago County. IL St Rt 251 intersects the following highways in Winnebago County. U.S. Rt. 20, at Rockford. BUSN. U.S. Rt. 20, at Rockford.