Horseshoe Island is an island in Green Bay in Door County, Wisconsin. The island is located offshore from Peninsula State Park and is part of the state park. The French explorer Jean Nicolet reportedly landed on the island. The island is part of the Town of Gibraltar, and lies offshore from the village of Ephraim, Wisconsin. Climate Gallery References External links Horseshoe Island, Web-Map of Door County, Wisconsin Islands of Door County, Wisconsin Lake islands of Wisconsin Islands of Lake Michigan in Wisconsin