Ridgefield NWR has a total of 5,150 acres of marshes, grasslands and woodlands. Preservation of the natural Columbia River floodplain is the management objective of the Carty (2-mile self guided hiking trail) Roth and Ridgeport Dairy units. The River 'S' (4.2 mile auto tour route and 1.2 mile seasonal hiking trail) and Bachelor Island units are managed to maximize habitat for waterfowl and other wetland wildlife.