Starting at St. Charles's eastern border with West Chicago, its name changes from Main Street to North Avenue, just east of the Kane/DuPage county line.

Illinois Route 64 then continues north onto LaSalle Drive for a very short distance until ending at U.S. Route 41 (Lake Shore Drive), while North Avenue continues east for less than one-half mile, changing its name to North Boulevard at Clark Street, and then continuing until its termination in a cul-de-sac at 200 East, just west of Lake Shore Drive.

North Avenue, signed as Illinois Route 64, travels east from Main Street at the St. Charles/West Chicago border.

Just west of the DuPage/Cook county line (while still in Elmhurst), the street intersects U.S. Route 20 and Interstate 290 (Eisenhower Expressway).

Together, the two highways cross the county line and then continue into Northlake (named after North Avenue and Lake Street).

The route continues as a border between Oak Park (south) and Chicago (north) until reaching Austin Boulevard.

On the northern side all of the Street in the City west of Kedzie was annexed with the Town of Jefferson effective June 29, 1889.