Horicon Marsh
（重定向自Horicon National Wildlife Refuge）
![](/Images/godic/202501/18/HoriconMarshBoardwalk1554.jpg")
![](/Images/godic/202501/18/Usa_edcp_relief_location_map1554.png")
![Location of Horicon Marsh](/Images/godic/202501/18/WIMap-doton-Horicon1554.png")
![A Purple Martin captured a Four Spotted Chaser](/Images/godic/202501/18/Purple_martin_71661554.jpg")
Horicon Marsh is a marsh located in northern Dodge and southern Fond du Lac counties of Wisconsin. It is the site of both a national and a state wildlife refuge. The extinct glacial lake is the largest freshwater cattail marsh in the United States.