The Wisconsin Ledge American viticultural area contains approximately 3,800 square miles, with approximately 320 acres of vineyards. 14 commercially-producing vineyards and wineries exist, yet widely dispersed, at approval of the AVA with an additional 70 acres projected to be planted. Wisconsin Ledge AVA lies in Door, Kewaunee, Manitowoc, Sheboygan, Ozaukee, Washington, Dodge, Fond du Lac, Calumet, Outagamie, and Brown Counties of northeast Wisconsin.
Largely surrounded by water, in the form of Lake Winnebago, the Fox River, Green Bay, and Lake Michigan the region is heavily affected by the lasting effects of ancient glacial activity and the moderating marine influence of the surrounding bodies of water.
The distinguishing features of Wisconsin Ledge are its geology, geography, climate, hydrology, and soils compared to the distinguishing features of the surrounding area. The fact that cold hardy grapes such as Marechal Foch are critical to surviving the winter months remains consistent. Only the most cold hardy hybrid grapes can survive.