Contoocook River

The Contoocook River is a 71-mile river in New Hampshire. It flows from Contoocook Lake on the Jaffrey–Rindge border to Penacook, just north of Concord, where it joins the Merrimack River. It is one of the few rivers in the state that flows mostly northward. Along the way it passes Peterborough, Bennington, Antrim, Hillsborough, Henniker, West Hopkinton and the village of Contoocook. It drains a basin of 766 square miles and falls more than 700 feet. Its main tributaries are Nubanusit Brook, the North Branch, the Warner River and the Blackwater River. Four covered bridges cross the river: one in Henniker, one on the Hancock–Greenfield line and two in Hopkinton.

Boating on the river falls into three main stretches. The upper river has a mix of quickwater and moderate rapids. Between Hillsborough and West Henniker the river has Class III–IV whitewater, including the Class IV Freight Train Rapids. A Class II reach runs about 2 miles through the center of Henniker. Below Contoocook Village down to the island in Penacook, the river is mostly flatwater and is used by motorboats, party boats, canoes and rowboats. The listed public access points include the Rolfe Canal Public Boat Ramp and the Penacook St. Boat Ramp in Concord, Riverway Park in Hopkinton, Grimes Park in Hillsborough and the Powdermill Pond Access Facility near Greenfield. A USGS gauge near Henniker, run in cooperation with the U.S. Army Corps of Engineers, reports flow and gage height.

The river has both cold-water and warm-water fish habitat. It is also part of the program to restore anadromous fish in the Merrimack River watershed. The rapids between Hillsborough and West Henniker are described as the river's best cold-water habitat.