The Killsnake River is a 19.7adj=midNaNadj=mid[1] river in eastern Wisconsin in the United States. It is a tributary of the South Branch of the Manitowoc River, which flows to Lake Michigan.
The river flows for its entire course in central Calumet County. It rises about 3miles east of Lake Winnebago and flows generally east-southeastwardly; it joins the South Branch of the Manitowoc River about 6miles east of Chilton in the Killsnake Wildlife Area.
The 5777acres surrounding the confluence of the Killsnake River with the South Branch Manitowoc River has been designated a wildlife refuge by the Wisconsin Department of Natural Resources.[2] The area is located entirely in the town of Rantoul.
There are four archaeological sites ranging from a major Early Paleo-Indian campsite from 9000 BC to a Potawatomi village from the mid-19th century AD located in the wildlife area,[3] and the site is listed on the National Register of Historic Places.