Constitution Marsh is a 270-acre (110 ha) fresh water and brackish tidal marsh located between Constitution Island and the eastern shores of the Hudson River in Garrison, New York. Together with 80 acres (32 ha) of bordering woodlands, it forms the National Audubon Society's Constitution Marsh Audubon Center and Wildlife Sanctuary. Part of Hudson Highlands State Park, it is one of five major tidal marshes along the Hudson River. Constitution Marsh is an Audubon Important Bird Area, and has been listed as a New York State Bird Conservation Area since the early 2000s. It is also recognized by the New York State Department of State as both a Significant Coastal Fish and Wildlife Habitat and a Scenic Area of Statewide Significance.