WIS 21 highlighted in red | ||||
Route information | ||||
Maintained by WisDOT | ||||
Length | 123.37 mi[1] (198.54 km) | |||
Major junctions | ||||
West end | ![]() ![]() ![]() | |||
East end | ![]() | |||
Location | ||||
Country | United States | |||
State | Wisconsin | |||
Counties | Monroe, Juneau, Adams, Waushara, Winnebago | |||
Highway system | ||||
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State Trunk Highway 21 (often called Highway 21, STH-21 or WIS 21) is a state highway in the U.S. state of Wisconsin. It runs east–west across the center of the state between Sparta and Oshkosh. The highway often serves as a direct route for travelers between Appleton and Oshkosh to Tomah and La Crosse. It is a two-lane surface road for nearly all of its length, with the exception of a few urban arterials of four or more lanes. The section of WIS 21 between Fort McCoy and I-94 in Tomah is classified as a "Major STRAHNET Connector", while the route past I-94 is classified as a "Non-Interstate STRAHNET Route".[1]