Black River, NY
The Black River is a 125-mile-long (201 km) blackwater river that empties into the eastern end of Lake Ontario on the shore of Jefferson County, New York in the United States of America. The origin of the name is not clear, but it may stem from the natural tannic acid that darkens the water in places.
The river's source is in various locations, including Little Black Creek and North Lake, in the foothills of the Adirondack Mountains in northern New York.
The river ends at Lake Ontario west of the City of Watertown. For the last few miles it forms the boundary between the Towns of Brownville and Hounsfield.