Our purpose is to provide refuge and breeding grounds for migratory birds and other wildlife. The Slough is all that remains of a pre-glacial riverbed. The name “Union” refers to the connection of two watersheds, the Blue Earth River and the east fork of the Des Moines River. Native Americans called this area Mini Akapan Kaduza, meaning “water which runs both ways”. During the early settlement times, Union Slough covered 8,000 acres and was considered useless for farming. Many levees and ditches were built in this area in an attempt to control water levels and improve the area for agriculture. In spite of these habitat changes, the area continued to support an abundance of waterfowl, as well as wetland and upland wildlife species. Refuge uplands surrounding the Slough still contain remnant tallgrass prairie, a rare commodity in an intensively cultivated area. Today, Union Slough National Wildlife Refuge encompasses 3,334 acres of both marsh and upland habitat.