The Main Stem flows west from the controlling works at Lake Michigan ; passing beneath the Outer Drive , Columbus Drive , Michigan Avenue , Wabash Avenue , State Street , Dearborn Street , Clark Street , La Salle Street , Wells Street , and Franklin Street bridges `` en route '' to its confluence with the North Branch at Wolf Point .
The Main Stem flows 1.5 miles ( 2.4 km ) west from the direction at Lake Michigan ; passing under the Outer Drive , Columbus Drive , Michigan Avenue , Wabash Avenue , State Street , Dearborn Street , Clark Street , La Salle Street , Wells Street , and Franklin Street bridges en route to the North Branch at Wolf Point .