Fox River enters Illinois near the town of Antioch where it flows more or less to the south for some 115 miles past the population centers of northeastern Illinois, including Chicago, before being subsumed by the larger Illinois River at Ottawa. Like many Illinois rivers it is a major tributary to the Illinois that provides various recreational opportunities. More than 7 million people who live in the greater Chicago metropolitan area come to enjoy themselves on Fox River. Sport fishing is a major recreational activity on the river, especially in the tail waters below the 15 major dams that impound the river into pools of varying lengths.

The most bountiful Illinois fishing spots can be found at the following dams: Yorkville, St. Charles, Montgomery, North Aurora, Dayton and McHenry. Spring and fall are the best seasons in which to catch the majority of sport-fishing species that inhabit Fox River. April and September are particularly good months to catch walleye, with many smallmouth bass taken right along with them.