Catchment area of the Wisconsin River
Its course is divided into three areas: the Upper Wisconsin from its origin, the Lac Vieux Desert in northeastern Wisconsin to Plover, the Middle Wisconsin Plover to the Wisconsin Dells and the Lower Wisconsin from the Wisconsin Dells up to its confluence with the Mississippi, about 16 km south of Prairie du Chien. Its largest tributaries are the rivers Tomahawk River, Big Rib River, Eau Claire River, Eau Pleine Big River, Yellow River, Lemonweir River, Baraboo River, Pine River and Kickapoo River. Larger towns along the river are (starting from the origin) Eagle River, Rhinelander, Tomahawk, Merrill, Wausau, Mosinee, Stevens Point, Wisconsin Rapids, Wisconsin Dells, Portage, Sauk City and Prairie du Sac. Due to the relatively large height difference between the origin and the mouth (325 m ), the Wisconsin dammed in many places and used to generate electricity. Overall, 26 hydropower plants are by the river.
In Portage Wisconsin River just 3.2 km from the River Fox River. The junction of these rivers established a major route between Lake Michigan and the Mississippi for Indians and French explorers. Due to ideal conditions of Wisconsin is a known hibernation site for Bald Eagles in Sauk City and Prairie du Sac.