The large, red five-pointed star placed in the middle of the flag symbolizes one of the six geographical regions of Cook County, the city of Chicago. The green five-pointed stars represent the other five suburban regions of Cook County (North, Northwest, West, Southwest, South), with the color green symbolizing nature in Cook County. The five-pointed stars represent the five main missions of Cook County. The light gray background of the flag represents the various modes of transportation within the County. Finally, the two light blue stripes on both sides of the flag represent Lake Michigan and the Chicago River.