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 Mass ...

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 Lond ...

. Its watershed includes the towns of Boxborough, Harvard, Littleton, Ayer, Groton, Westford,

Tyngsborough Tyngsborough (also spelled Tyngsboro) is a town in northern Middlesex County, Massachusetts, United States. Tyngsborough is from Boston along the Route 3 corridor, and located on the New Hampshire state line. At the 2020 census, the town pop ...

, 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 North Chelmsford is an unincorporated village in the town of Chelmsford, Massachusetts, United States. Although North Chelmsford has its own zip code (01863), library, post office, fire station, water district, and local calling area, it is ot ...

. Stony Brook is parallel through its course by the

Stony Brook Railroad The Stony Brook Railroad (formally the Stony Brook Railroad Corporation), chartered in 1845, was a railroad company in Massachusetts, United States. The company constructed a rail line between the Nashua and Lowell Railroad's main line at the v ...

. 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