The Marsh Haven entrance, on the north side of State Hwy 49
Marsh Haven Nature Center is located on the north end of the Horicon Marsh, just three miles east of Waupun, Wisconsin on State Road 49. The Horicon Marsh is a Wetland of International Importance and at almost 33,000 acres, it is the largest freshwater cattail marsh in the United States. Marsh Haven Nature Center is separate from the Federal Refuge and the State Wildlife area, and is nestled on 46 acres just outside of the Horicon National Wildlife Refuge boundary.