The Fox River continues down into Illinois, meandering through the northwest suburbs of Chicago, through Elgin, Illinois, one of the larger towns there, where it supports many a riverboat casino. A large bridge across the river seems to be a staple in the downtown areas of many old villages along the way. The river valley slopes gently, and, in some places, where it's as many as 10 miles across, you can see the opposite side. Containing hills and dense vegetation, it's a little more interesting than the miles of flat farmland or the metropolitan areas that lie beyond.

It's clear that many of these towns were originally founded solely because of the river's presence.