The North Branch Marsh River is a 1 miles (1.6 km) tidal river in the town of Frankfort

Frankfort, Maine

Frankfort is a town in Waldo County, Maine, United States. The population was 1,041 at the 2000 census.-History:Frankfort is the oldest town on the Penobscot River, first settled in the 1760s by Massachusetts soldiers from nearby Fort Pownall...

, Waldo County

Waldo County, Maine

Waldo County is a county located in the U.S. state of Maine. As of 2010, the population was 38,786. Its county seat is Belfast.Waldo County was founded on 7 February 1827 from a portion of Hancock County...

, 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...

. It is a tributary of Marsh Bay, an arm of the tidal Penobscot River

Penobscot River

The Penobscot River is a river in the U.S. state of Maine. Including the river's West Branch and South Branch increases the Penobscot's length to , making it the second longest river system in Maine and the longest entirely in the state. Its drainage basin contains .It arises from four branches...

.

The North Branch Marsh River is fed by Marsh Stream, a 33.6 miles (54.1 km) river in central Maine. Marsh Stream rises at 44.4812°N 69.2170 °W on the north slopes of Frye Mountain, on the boundary between the towns of Montville

Montville, Maine

Montville is a town in Waldo County, Maine, United States. The population was 1,002 at the 2000 census.-Geography:According to the United States Census Bureau, the town has a total area of , of which, of it is land and of it is water....

 and Knox

Knox, Maine

Knox is a town in Waldo County, Maine, United States. The town was named for General Henry Knox, the first United States Secretary of War. The population was 747 at the 2000 census.-Geography:...

. It flows northeast through Knox, Brooks

Brooks, Maine

Brooks is a town in Waldo County, Maine, United States. The population was 1,022 at the 2000 census.The town was named after John Brooks, the Federalist candidate for Governor of Massachusetts in 1815-1816, when the town incorporated. The town of Dexter, which incorporated the same year, was named...

, and Monroe

Monroe, Maine

Monroe is a town in Waldo County, Maine, United States. The town was named for President James Monroe. The population was 882 at the 2000 census.-Geography:...

, then becomes the boundary between the towns of Winterport

Winterport, Maine

Winterport is a town in Waldo County, Maine, United States. The population was 3,602 at the 2000 census. Each August the town hosts the Winterport Music Festival.-History:...

and Frankfort. Turning southeast, the stream flows through the village of Frankfort, where it reaches tidewater and becomes the North Branch Marsh River.