The Marsh River is a 3.9 miles (6.3 km) tidal river in Newcastle

Newcastle, Maine

Newcastle is a town in Lincoln County, Maine, United States. The population was 1,748 at the 2000 census. The village of Newcastle is located in the western part of the town, on the Damariscotta River...

, Maine

Maine

Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...

, in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It is a tributary of the Sheepscot River

Sheepscot River

The Sheepscot River is a river in the U.S. state of Maine. Its lower portion is a complex island estuary with connections to the Kennebec River downstream of Merrymeeting Bay.-Route:...

.

The Marsh River is formed at the confluence of Deer Meadow Brook and the outlet of Sherman Lake in the western corner of Newcastle and flows west, north, and west again to join the Sheepscot at the town boundary between Newcastle and Wiscasset.