The Cohansey River originates in Central Salem County at Cool Run and Bostwick Lake and meanders for nearly 30 miles through Cumberland County before reaching the Delaware Bay. As 
the second largest tributary to the Delaware Bay, the Cohansey River represents one of the region’s greatest, yet least protected natural treasures. It is also one of the most scenic and unspoiled of all the rivers in the Delaware Estuary.
The 111-square-mile Cohansey River Watershed encompasses one of the largest expanses of quality wetlands in the state. It is home to eleven townships and maritime villages, including one of the Bayshore’s largest urban centers, Bridgeton, and two National Register historic districts. Other townships included in the Cohansey River Watershed are Upper Pittsgrove Township, Alloway Township, Upper Deerfield Township, Deerfield Township, Shiloh Borough, Stow Creek Township, Hopewell Township, Fairfield Township, Greenwich Township, and Lawrence Township.
The Upper Cohansey River is freshwater and bound by important agricultural land including cultivated fields and orchards. Sunset Lake and Mary Elmer Lake are among 20 major impoundments in this drainage basin. The tidal head begins just below Sunset Lake in the largely wooded, 1,000-acre Bridgeton City Park. The Lower Cohansey River corridor is dominated by an immense brackish tidal estuary, bordered by a wildlife-rich mixture of important farmland, woodlands and wetlands.