The Stop River is a low and marshy stream in Medfield, Massachusetts

Medfield, Massachusetts

Medfield is a town in Norfolk County, Massachusetts, United States. The population was 12,024 according to the 2010 Census. Medfield is an affluent community about 17 miles southwest of Boston....

, and partly forming the border between Norfolk

Norfolk, Massachusetts

Norfolk is a town in Norfolk County, Massachusetts, United States with a population of 10,460 people in 2,818 households at the 2000 census. Formerly known as North Wrentham, Norfolk broke away to become an independent town in 1870.-History:...

 and Walpole

Walpole, Massachusetts

Walpole is a town in Norfolk County, Massachusetts, United States. It is located about south of Boston and north of Providence, Rhode Island. The population was 24,070 at the 2010 census. Walpole was first settled in 1659 and was considered a part of Dedham until officially incorporated in 1724...

. The river rises near Highland Lake in Walpole

Walpole, Massachusetts

Walpole is a town in Norfolk County, Massachusetts, United States. It is located about south of Boston and north of Providence, Rhode Island. The population was 24,070 at the 2010 census. Walpole was first settled in 1659 and was considered a part of Dedham until officially incorporated in 1724...

, flows 9.3 miles (15 km) northwards to join the Charles River

Charles River

The Charles River is an long river that flows in an overall northeasterly direction in eastern Massachusetts, USA. From its source in Hopkinton, the river travels through 22 cities and towns until reaching the Atlantic Ocean at Boston...

 in Medfield

Medfield, Massachusetts

Medfield is a town in Norfolk County, Massachusetts, United States. The population was 12,024 according to the 2010 Census. Medfield is an affluent community about 17 miles southwest of Boston....

, and ultimately drains into Boston Harbor

Boston Harbor

Boston Harbor is a natural harbor and estuary of Massachusetts Bay, and is located adjacent to the city of Boston, Massachusetts. It is home to the Port of Boston, a major shipping facility in the northeast.-History:...

.

The Medfield Rhododendrons

Medfield Rhododendrons

The Medfield Rhododendrons is a nature reserve established in 1934 in Medfield, Massachusetts and is managed by the Trustees of Reservations. The site contains the largest area of Rhododendron maximum in the state, which are currently listed as threatened by the Massachusetts Natural Heritage and...

 reservation, operated by The Trustees of Reservations

The Trustees of Reservations

The Trustees of Reservations is a non-profit land conservation and historic preservation organization dedicated to preserving natural and historical places in the Commonwealth of Massachusetts. It is the oldest regional land trust in the world and has 100,000 dues-paying members...

, is an important and rare stand of Rhododendron maximum along the river in Woodridge Street, Medfield.