About the Watershed
The North Branch of the Chicago River Watershed planning area covers 95 square miles, with northern and southern boundaries roughly extending from Illinois Route 132 (Grand Avenue) in the City of Waukegan in Lake County south to Dempster Street in Morton Grove in Cook County.
The North Branch of the Chicago River is formed from three tributary streams: the 17 mile Skokie River (or East Skokie), 24 mile Middle Fork (also known as the West Skokie), and the 14 mile West Fork. From their origins in Lake County, these tributaries flow south into Cook County where they converge to form the main stem of the North Branch.