Jefferson County, WI is located between Madison and Waukesha in south eastern part of the state along Lake Koshkonong. Jefferson is known for farming, farmers markets, car shows, green country side, area parks, hunting, fishing which also has Madison Audubonâs Faville Grove Sanctuary, Glacial Drumlin State, Rock Lake, Rock River, Lake Ripley plus a couple communities including; Palmyra, Fort Atkinson, Jefferson, Johnson Creek, Lake Mills, Ixonia, Waterloo, Watertown and part of Whitewater. It's surrounded by 5 other Counties; Dodge, Waukesha, Walworth, Rock and Dane. On this page you will find houses, log cabins, mobile homes, raw land and hunting acreage located in the county listed by real estate agents. Jefferson County, Wisconsin GIS MAP Information!