U.S. Federal Route 67 is the main north-south highway in Warren County. It is a four-lane highway from the Mc Donough/Warren County Line to near Monmouth. North of Monmouth it is a two lane highway to the Warren/Mercer County Line. U.S. Rt. 67 passes through the following town in Warren County. Monmouth
U.S. Rt. 67 is multi-plexed in Warren County. Illinois State Route 110, from the Mc Donough/Warren County Line to Monmouth.
Branches of U.S. Rt. 67 in Warren County. NB U.S. Rt. 67/IL St Rt 110 at the Mc Donough/Warren County Line. A Warren County mile marker. NB U.S. Rt. 67 near Swan Creek. NB U.S. Rt. 67/IL St Rt 110 south of Roseville. NB U.S. Rt. 67/IL St Rt 110 on the northwest side of Roseville. NB U.S. Rt. 67 south of U.S. Rt. 34. EB U.S. Rt. 34/NB U.S. Rt. 67 near Monmouth. EB U.S. Rt. 34/IL St Rt 164; NB U.S. Rt. 67 on the northwest side of Monmouth. A street sign in Monmouth. NB U.S. Rt. 67/EB IL St Rt 135 near Alexis.