Stony Brook is a tributary of the

Merrimack River The Merrimack River (or Merrimac River, an occasional earlier spelling) is a river in the northeastern United States. It rises at the confluence of the Pemigewasset and Winnipesaukee rivers in Franklin, New Hampshire, flows southward into Mas ...

in northeastern

Massachusetts Massachusetts (Massachusett language, Massachusett: ''Muhsachuweesut assachusett writing systems, məhswatʃəwiːsət'' English: , ), officially the Commonwealth of Massachusetts, is the most populous U.S. state, state in the New England ...

, joining the Merrimack at

Chelmsford Chelmsford () is a city in the City of Chelmsford district in the county of Essex, England. It is the county town of Essex and one of three cities in the county, along with Southend-on-Sea and Colchester. It is located north-east of London a ...

. Its watershed includes the towns of Boxborough,

Harvard Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

, Littleton,

Ayer Ayer may refer to: Places * Ayer, Massachusetts, United States ** Ayer (CDP), Massachusetts, the central village in the town of Ayer ** Ayer (MBTA station), commuter rail station * Aller, Asturias, a municipality in Spain known in Asturian as A ...

, Groton, Westford, Tyngsborough, and Chelmsford. Its farthest upstream tributary is Beaver Brook, originating in Wolf Swamp in Boxborough, upstream (southwest) of the mouth of Stony Brook in the Merrimack. Beaver Brook passes through Mill Pond in the center of Littleton and ends at Forge Pond at Forge Village in Westford. Stony Brook originates as the dammed outlet of Forge Pond and continues northeast past Graniteville, the Stony Brook Reservoir (not to be confused with the Stony Brook Reservoir in Weston and Waltham), Westford Station, Nabnasset, Brookside Station, and West Chelmsford, reaching the Merrimack at North Chelmsford. Stony Brook is parallel through its course by the Stony Brook Railroad. The Great Stony Brook Twister is a well known historical event relating to the Brook. Along with the Twister, there is also allegedly a mythical being known as the "Chafe Man" that roams the Brook at night.

References

Rivers of Middlesex County, Massachusetts {{massachusetts-river-stub