The Fox River is a 202-mile-long (325 km) tributary of the Illinois River, flowing from southeastern Wisconsin to Ottawa, Illinois in the United States. The Wisconsin section was known as the Pishtaka River in the 19th century. There is another Fox River in Wisconsin that flows through Lake Winnebago into Green Bay. There are also two other "Fox Rivers" in southern Illinois: the Fox River (Little Wabash tributary) and a smaller "Fox River" that joins the Wabash River near New Harmony, Indiana.
The Fox River (Illinois River tributary) is known locally as an excellent fishery with opportunities for Smallmouth Bass, Flathead Catfish, and Walleye. The river’s watershed encompasses 1720 square miles in Illinois and 938 square miles in Wisconsin.

Quelle: Wikipedia