The Rock River is a tributary of the Mississippi River, approximately 285 miles (459 km) long, in the U.S. states of Wisconsin and Illinois. It rises in southeast Wisconsin, in southwest Fond du Lac County, approximately 10 miles (16 km) south of Ripon and 25 miles (40 km) southwest of Lake Winnebago. It flows south, through the Horicon National Wildlife Refuge, then meanders southward draining the area of southeast Wisconsin between the Wisconsin River and Lake Michigan. It passes Watertown, Jefferson, and receives the Bark River at Fort Atkinson. In northern Rock County it receives the Yahara River, and flows southward through Janesville and Beloit into northern Illinois, where it receives the Pecatonica River 5 miles (8 km) south of the state line. It flows south through Rockford, then southwest across northwestern Illinois. passing Oregon, Dixon and Rock Falls, where it becomes navigable. It joins the Mississippi at Rock Island. The Rock River is well situated to provide fishing opportunities for a sizable portion of northern Illinois' population. Fortunately the river is up to the task, with populations of channel catfish, walleye, northern pike, largemouth and smallmouth bass, sauger, white bass, bluegill, flathead catfish, drum and bullheads. The river provides an aquatic resource of some 12,400 acres. Dams at Rock Island, Milan, Sterling(Rock Falls), Dixon, Oregon, Rockford, and Rockton cause tailwater and lake habitats in addition to the slough, side channel, main channels.Tailwater habitat, found below each dam is fast turbulent water caused by the passage of water over the dams. Tailwaters receive heavy fishing pressure because fish congregate in these rough waters. Walleye, sauger and white bass are most frequently taken from tailwater areas. The Rock is a catfish stream -- more so than any other large stream in the state. Channels can be taken almost anywhere along its course and are the primary sport fish. Huge flatheads lurk in the deeper holes. "Cats" often hole up underneath old stumps, downstream of fallen trees, around log jams and in washout holes along banks. They can frequently be found on the edge of the main channel border habitat where the bottom drops sharply to deeper water in the main channel. Northern pike are not abundant in any stream of this state, but apparently the largest population is in the Rock River. The best time to fish for them is early spring (March) when they move to spawn. Bullheads may be caught during the warmer months in quiet shallow areas. Walleye and the less common sauger are taken in the tailwater areas in March and April.Bluegill can be taken during the summer months on a variety of baits.
The Rock River is a tributary of the Mississippi River, approximately 285 miles (459 km) long, in the U.S. states of Wisconsin and Illinois.