The river enters Will County, Illinois, for only a short distance before joining the Des Plaines River. Here, in the Des Plaines Fish and Wildlife Area, the two rivers form the Illinois River for the journey to the Mississippi River. Because of the river's wide valley and historic great marsh, there are few towns on the river throughout the entire length of Indiana. Most towns are located either north or south, on high ground, just outside the marshes. Today, the marshes have been drained and it is not apparent why the towns are so far from the river. Kankakee River (main stem)  Yellow River Branch  Iroquois River Branch