Concord River

Concord River
The Concord River at the Old Bridge, Concord, Massachusetts, circa 1900.
Country	United States
Basin features
Main source	Sudbury and Assabet Rivers, Concord, Massachusetts 50 ft (15 m) 42°27′55″N 71°21′29″W / 42.4654°N 71.3580°W / 42.4654; -71.3580
River mouth	Merrimack River, Lowell, Massachusetts 42°38′47″N 71°18′09″W / 42.6465°N 71.3025°W / 42.6465; -71.3025Coordinates: 42°38′47″N 71°18′09″W / 42.6465°N 71.3025°W / 42.6465; -71.3025
Basin size	377 sq mi (980 km2)
Physical characteristics
Length	16.3 mi (26.2 km)

The Concord River is a 16.3-mile-long (26.2 km) tributary of the Merrimack River in eastern Massachusetts in the United States. The river drains a small rural and suburban region northwest of Boston. One of the most famous small rivers in U.S. history, it was the scene of an important early battle of the American Revolutionary War and was the subject of a famous 19th-century book by Henry David Thoreau.

The river begins in Middlesex County, formed by the confluence of the Sudbury and Assabet rivers at Egg Rock, near the Concord town center. It flows generally north, from eastern Concord (along the northwestern edge of the Boston metropolitan area), joining the Merrimack River from the south on the eastern side of Lowell. It is a gently flowing stream with little variation in topography along most of its route. Its drainage basin stretches into Worcester County and includes 36 towns within Massachusetts.

Native Americans called it the Musketaquid or "grass-grown" river, because its sluggish waters abound in aquatic or semi-aquatic vegetation and its banks are fringed with wild grasses and sedges which stretch for miles along both sides of this placid stream. This creates a good environment for a variety of fish, including Bass, Shad, and Alewife (River Herring), Pickerel, Carp, and American eel. Native Americans wove sticks in intricate designs to trap Alewives and other migrating fish at the mouths of rivers throughout this region.