The Blackwater National Wildlife Refuge was established in 1933 as a waterfowl sanctuary for birds migrating along the critical migration highway called the Atlantic Flyway. The refuge is located on Maryland's Eastern Shore, just 12 miles south of Cambridge, Maryland in Dorchester County, and consists of over 27,000 acres (110 km²) of freshwater impoundments, brackish tidal wetlands, open fields, and mixed evergreen and deciduous forests.