The Stop River is a low and marshy stream in Medfield, Massachusetts, and partly forming the border between Norfolk and Walpole. The river rises near Highland Lake in Norfolk, flows 9.3 miles (15.0 km)^[1] northwards to join the Charles River in Medfield, and ultimately drains into Boston Harbor.

The Medfield Rhododendrons reservation, operated by The Trustees of Reservations, is an important and rare stand of Rhododendron maximum along the river in Woodridge Street, Medfield.

References

^ U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National Map, accessed April 1, 2011

Buzzards Bay	Acushnet River Agawam River Back River Copicut River Crooked River Mattapoisett River Nasketucket River Paskamanset River Pocasset River Sippican River Slocums River Wankinco River Westport River Weweantic River
Nantucket Sound	Bass River Bumps River Childs River Coonamesset River Mashpee River Mitchell River Oyster Pond River Popponesset Creek Quashnet River Santuit River
Others	Tiasquam River

Cape Cod Bay	Bluefish River Eel River Herring River Jones River Little Pamet River Pamet River Town Brook
Massachusetts Bay	Aberjona River Alewife Brook Canton River Charles River Chelsea Creek Cochato River Fore River Fresh River Indian Head River Malden River Millers River Monatiquot River Muddy River Mystic River Neponset River North River Saugus River Stony Brook (Boston) Stony Brook (Waltham) Stop River Weir River Weymouth Back River
Merrimack River Watershed	Artichoke River Assabet River Back River Beaver Brook Cochichewick River Concord River Little River Merrimack River Nashua River Nissitissit River North Nashua River Phillips Brook Powwow River Quinapoxet River Salmon Brook Shawsheen River Souhegan River South Branch Souhegan River South Nashua River Spicket River Squannacook River Stillwater River Sudbury River Trout Brook Vine Brook Whitman River
Others	Annisquam River Blackwater River Eagle Hill River Egypt River Ipswich River Jericho Creek Roger Island River Rowley River Skug River

Connecticut River Watershed	Burnshirt River Chapel Brook Chicopee River Connecticut River Cranberry River Deerfield River East Brookfield River Farmington River Fall River Five Mile River Green River Hubbard River Manhan River Mill River (Northampton) Mill River (Springfield) Millers River Mirey Brook North Branch Millers River North Branch Westfield River North River Otter River Quaboag River Scantic River Seven Mile River Tarbell Brook Ware River Westfield River
Housatonic River Watershed	Housatonic River Konkapot River Schenob Brook Umpachene River
Thames River Watershed	French River Quinebaug River

Mount Hope Bay (Taunton River Watershed)	Assonet River Canoe River Cedar Swamp River Cocasset River Cotley River Forge River Hockomock River Matfield River Mill River Nemasket River Poor Meadow Brook Quequechan River Rumford River Salisbury Plain River Satucket River Segreganset River Shumatuscacant River Snake River Taunton River Three Mile River Town River Wading River Winnetuxet River
Providence River Watershed	Abbott Run Blackstone River Bungay River Chockalog River Mill River Mumford River Peters River Quinsigamond River Sevenmile River Tannery River Ten Mile River West River Wilde River
Others	Barrington River Cole River Coles Brook Kickamuit River Lees River Palmer River Runnins River

Hudson River Watershed	Hoosic River Kinderhook Creek