608
The 608 area code currently covers much of southwestern Wisconsin, including the capital city of Madison as well as the cities of Waunakee,Mount Horeb, Verona, Sun Prairie, Monroe, Platteville, Lancaster, Portage, Baraboo, Wisconsin Dells, Beloit, Janesville, La Crosse, Prairie du Chien, Prairie du Sac, Sauk City, Viroqua and Sparta. It was created in 1955 as a split from area code 414, and was the third area code created in Wisconsin.
-Wikipedia