Wisconsin State Route 21 is an east-west highway in Central Winnebago County. It runs from the Waushara/Winnebago County Line, northeast of Berlin, to U.S. Rt. 45, in Oshkosh. WI St Rt 21 passes through the following towns in Winnebago County. Omro Oshkosh
WI St Rt 21 is not multi-plexed in Winnebago County. WI St Rt 21 intersects the following highways in Winnebago County. Wisconsin State Route 116, at Omro. Interstate 41, at Oshkosh. U.S. Rt. 41, at Oshkosh. U.S. Rt. 45, at Oshkosh.
A BGS on NB I-41/U.S. Rt. 41. A BGS on the ramp from NB I-41/U.S. Rt. 41. EB WI St Rt 21 at Punhoqua Street in Oshkosh. A junction marker on NB U.S. Rt. 45.
