Illinois State Route 251 is a major surface artiery in Western-La Salle County. It provides access to the main shopping locations on the northside of Peru. This is also one of the few state highways in La Salle County to go from the northern boarder to the southern boarder. IL St Rt 251 passes through the following towns. Mendota
IL St Rt 251 is multi-plexed in La Salle County. U.S. Rt. 52, from Mendota to near Troy Grove.
IL St Rt 251 intersects the following hihgways in La Salle County. U.S. Rt. 52, near Mendota