Wisconsin Highway 57 (often called Highway 57, STH-57 or WIS 57) is a state highway Wisconsin, United States. It runs from its southern terminus at Wisconsin Highway 59 in Milwaukee to its northern terminus at Wisconsin Highway 42 in Sister Bay. Much of WIS 57 parallels Interstate 43 and WIS 42, particularly from Saukville to its northern terminus in Sister Bay. The highway is concurrent with I-43 for in Ozaukee County. Like most Wisconsin state highways, WIS 57 is maintained by the Wisconsin Department of Transportation (WisDOT).