The Rock River commences its journey slightly west of West Bend in Wisconsin. The river meanders south through Wisconsin, covering about 130 miles before entering Illinois. At this point, Rock River deviates southwest. After about 155 miles, it flows into the Mississippi River.
The Rock River is older than Lake Michigan. It once was a tributary to the Illinois River, which feeds into the lake. However, during the Ice Age, rock effectively blocked the river and the water diverted to take an easier course, which takes it to the Mississippi River, as of 2011. Water from the Rock River permeates through the rocks and travels underground, but has been renamed Princeton Aquifer. It is thought Rock River was so named, because most of the river bed is rocky, rather than mud.
The Uses of the Rock River
Original settlers along the Rock River intended to use the river as a means of transportation, and, for some time, they probably did. The lush areas each side of the river provided good fertile soil for growing crops. However, the advent of the railroad halted the practice of using the river for commercial transportation. The mills around Sterling, to the south of Rockford, were originally powered by water from the river. As of 2011, a dam provides hydro electricity for the City of Rock Falls, although Rock River's main use is for recreational purposes.
The Rock River Route
Rock River enters Illinois at the north near South Beloit and runs along both sides of Boney Island. It continues southeast and flows through Rockford, Sterling and Rock Falls. At the eastern edge of Sterling, the Rock River widens dramatically into Lake Sinnissippi; the opposite end of the lake is where the Rock Falls dam has been built. It finally passes Rock Island, before flowing into the Mississippi.
Fishing the Rock River
The Rock River has an abundance of freshwater fish, the largest of which is the flathead cat, which can weigh in at more than 40 lbs. Other species include catfish, pike, bullhead, sauger, walleye and bluegill. The Illinois Department of Natural Resources is keen to maintain the river in good condition so fish can thrive and to ensure the river is abundantly stocked.
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