The Kinnickinnic River, called the Kinni for short, is a 25-mile-long river in northwestern Wisconsin in the United States. It is listed as a Class I trout stream. The Kinnickinnic River arises from springs in St. Croix County and flows in a southwesterly direction before emptying into the St. Croix River in Kinnickinnic State Park. The city of River Falls, Wisconsin, named after a waterfall on the Kinnickinnic, is situated on the river. The name "Kinnickinnic" is a word from the Anishinaabe language, and refers to tobacco mixed with other plant material for smoking.[1] The first settler along the Kinnickinnick River was Joel Foster. He spent his first winter in a walled-in cave overhang at junction falls near where the power plant now stands.
The Kinnickinnic is composed of two types of river.[2] Above River Falls, the river flows slowly, with a sandy/silty bottom and a narrower bed. Below River Falls, the bed is wider and is generally composed of stone rather than sand or silt. A substantial amount of silt and sand are deposited in the delta, enough that that section of the St. Croix is known as the "Kinnickinnic Narrows."[3] The water is slightly colder above River Falls than below, as the dam in the city allows the water to sit and warm up before continuing.
The differences in the stream make for differences in the fish population.[2] The upper section of the river contains very high numbers of trout that are of smaller size. The warmer water below River Falls supports more minnow and crustacean life, which can support larger trout, though in fewer numbers. The extreme case of this is near the delta, where the water becomes even warmer, and the river supports warmer-water species such as smallmouth bass.