The Kinnickinnic River, called the Kinni for short, is a river in northwestern Wisconsin in the United States. The Kinni is a cold water fishery supporting a population of native Brook Trout and naturally reproducing Brown Trout. The Kinnickinnic River is officially designated as a Class I trout stream by the Wisconsin Department of Natural Resources. This means it is a "high quality" trout water that has populations of wild trout. Also, these streams do not need stocking with hatchery trout.