Sumner is a town in Jefferson County, Wisconsin, United States. The population was 832 at the 2010 census. The census-designated place of Lake Koshkonong and the unincorporated communities of Busseyville, Carcajou, Glenn Oaks Beach, Koshkonong Manor, and North Shore are located within the town. The community of Blackhawk Island is located partially in the town.
Sumner is a town in Jefferson County, Wisconsin, United States. The population was 832 at the 2010 census The census-designated place of Lake Koshkonong and the unincorporated communities of Busseyville, Carcajou, Glenn Oaks Beach, Koshkonong Manor, and North Shore are located within the town. The community of Blackhawk Island is located partially. in the town.