There are many different groups and organizations in Wisconsin that pilots and or aviation enthusiasts may join

Experimental Aircraft Association
Note there are many small EAA chapters found throughout the State that you can become a part of as well.

Wisconsin Airport Manager's Association

Wisconsin Aviation Trades Association

Wisconsin Business Aviation Association

Wisconsin Flying Farmers

Iola Dinner Club - Central County Flyers Association

Wisconsin Bureau of Aeronautics

Midwest Flyer - A Flying Magazine Made In Wisconsin. It is about news and flying in the Midwest (Wisconsin, Minnesota, Illinois, Iowa, Dakotas).

Wisconsin Aviation Conference