The Housatonic River ( ) is an approximately long river in western Massachusetts and western Connecticut in the United States. It flows south to southeast, and drains about of southwestern Connecticut into Long Island Sound.
History
Indigenous history
Indigenous people began using the river area for fishing and hunting at least 6,000 years ago. By 1600, the inhabitants were mostly Mohicans and may have numbered 30,000.
The river's name is derived from the Mohican phrase "usi-a-di-en-uk", translated as "beyond the mountain place" or "river of the mountain place". It is referred to in the deed by which a group of twelve colonists called "The Proprietors" captured the land now called Sherman and New Fairfield as "Ousetonack". Samuel Orcutt, a 19th-century historian, explained the term's pronunciation as "more properly...Howsatunnuck" and also noted an early spelling in the form of "Oweantinock". Prior to the 18th century, the river was alternatively known as the Pootatuck River. Accounts differ on the origin of this name, with some claiming that Pootatuck is an Algonquian term translating to "river of the falls" while others relate the term was eponymous, reflecting the name of the tribe that had their principal village along the river in the area of Newtown, Connecticut. "Pootatuck River" eventually came to refer a lesser tributary in the Housatonic watershed which empties into the Housatonic River at Sandy Hook, Connecticut.
The river passes through land that was formerly occupied primarily by native people of Algonquian lineage, typically living in villages of two to three hundred families housed in hide wigwams. These native inhabitants burned the forests along the Housatonic Valley in the autumn to keep the underbrush down, a practice which was customary throughout Connecticut prior to European settlement.
thumb|Housatonic river by Shelton at sunset.
One notable native was Chief Squantz of the Schaghticoke tribe, who still hold a portion of the former reservation on the west side of the Housatonic River, in what is now called the town of Kent.
Cultural references
Lydia Sigourney's poem The Housatonic is in her volume, Scenes in my Native Land, 1845, where it accompanied by descriptive text on the river and its neighbourhood.
The United States Navy named a ship for the Housatonic River. The has the distinction of being the first ship in history to be sunk by a submarine, the Confederate vessel CSS H.L. Hunley, in 1864.
Inspired by the river during his honeymoon, the American classical music composer Charles Ives wrote "The Housatonic at Stockbridge" as part of his composition Three Places in New England during the 1910s, drawing his text from a poem of the same name by Robert Underwood Johnson. The town of Stockbridge is located in southwestern Massachusetts. The river enters Stockbridge on the east side of town before turning south toward Connecticut.
There was a 1962 American nuclear weapon test of the same name; several such tests used Native American words as codewords.
UFO sighting and monument
In 1969, nine-year-old Thom Reed and his family claimed to see a bright light rise from the Housatonic River, then found themselves inside "what appeared to be an airplane hangar," where they saw creatures that "resembled large insects." Supporters of the family erected a memorial to the incident at the Old Covered Bridge in Sheffield, Massachusetts, in 2015. The 5,000-pound memorial was removed by the town in 2019. The incident featured in a 2020 episode of Unsolved Mysteries on Netflix.
Ecology and wildlife
Historically, the Housatonic River and its Naugatuck River tributary hosted the southernmost spawning runs of the Atlantic salmon (Salmo salar). The Salmon Creek tributary of the Housatonic River may have been named for this salmonid, which can reach up to .
Pollution
PCBs
thumb|Cleanup activity at one of the GE Pittsfield plant Superfund sites.
From circa 1932 until 1977, the river received PCB pollution discharges from the General Electric (GE) plant at Pittsfield, Massachusetts. The U.S. Environmental Protection Agency (EPA) designated the Pittsfield plant and several miles of the Housatonic as a Superfund site in 1997, and ordered GE to remediate the site. EPA and GE began a cleanup of the area in 1999. Most of the PCBs used in the United States during this period were made by Monsanto. Aroclor 1254 and Aroclor 1260, made by Monsanto, was a primary contaminant of the pollution in the Housatonic River. Although the water quality has improved in recent decades, and some remediation has taken place, the river continues to be contaminated by PCBs.
Between 2005 and 2018 GE completed remediation and restoration of the 10 manufacturing plant areas within the city, and continues to conduct inspection, monitoring and maintenance activities. Additional remediation is planned for the downstream polluted areas of the river. The highest concentrations of PCBs in the Housatonic River are found in Woods Pond in Lenox, Massachusetts, just south of Pittsfield, where they have been measured up to 110 mg/kg in the sediment.
Birds, such as ducks, and fish that live in and around the river contain significant levels of PCBs and can present health risks if consumed. As of 2025 fish consumption advisories remain in effect for both the Massachusetts and Connecticut portions of the river.
;"Rest of River" settlement agreement
Negotiations regarding how to clean up the contaminated areas south of Pittsfield continued for many years following the initial Superfund site designations, involving GE, EPA, local governments, citizen groups and other stakeholders. In February 2020 EPA announced a settlement agreement involving GE, EPA and most of the concerned parties, to remove contaminated sediment from the river. Following a public comment period, EPA issued a permit in December 2020 for the final cleanup phase. In 2021 two of the citizen groups that were parties to the settlement filed an appeal of the permit, criticizing the design of the planned landfill. In February 2022 the US Environmental Appeals Board (EAB) denied the permit appeal. Two citizen groups appealed the EAB decision to the First Circuit Court of Appeals, and in July 2023 the court rejected the plaintiffs' challenge.
In March 2025 EPA issued a conditional approval for GE's proposed disposal facility for low-level contaminated materials in the Town of Lee. Site preparation activities are expected to start in late 2025. Highly contaminated soil will be removed and shipped to federally approved facilities outside the state. High mercury levels are measured in the sediment at the outflow delta of the Housatonic River into Long Island Sound.
Watershed and course
thumb|upright=1.2|Boardwalk Marina in Stratford
The Housatonic River watershed drains in western Connecticut and Massachusetts and eastern New York.
Recreation
thumb|View of the "fly fishing and paddling" section of the river during a snowstorm.
The Housatonic River is a popular whitewater paddling destination beginning at Falls Village, Connecticut, and continuing to Gaylordsville. Most of the river is quickwater and Class I whitewater with long sections of Class II-III whitewater. A deadly and extreme Class VI resides at Great Falls in Canaan (Falls Village) and is most likely not able to be paddled. The most dangerous and difficult section that is navigable is by Bulls Bridge, with Class V whitewater.
There are several minor and major dams along the river that form lakes. Most notable are two lakes in Connecticut, Lake Zoar, which borders Monroe, Newtown, Oxford, and Southbury, and Lake Lillinonah. Both lakes are major water-sport recreation outlets for the surrounding towns.
Two of the three lakes formed by the dams are used for rowing by clubs, schools, and to host regattas. Lake Lillinonah is used by the GMS Rowing Center and is host to the GMS Regatta. Lake Housatonic is used by the Yale University Crew Team at the Gilder Boathouse and by the New Haven Rowing Club. It is also host to the Derby Sweeps & Sculls and the Head of the Housatonic.
The Housatonic River is also a popular fly fishing destination. Fly fishing on the Housatonic River has been compared with western rivers and is among the finest for trout in the eastern United States. The most popular area for fly fishing is in Litchfield County, Connecticut, between the dam at Falls Village and Cornwall Bridge. The sections between Kent School and Bulls Bridge are also known for quality fly fishing. The area below Bulls Bridge thru Gaylordsville and the power plant in New Milford is dangerous and not recommended for swimming or entering the water as the currents are quite strong. Fish consumption advisories remain in effect for the Housatonic River in Connecticut as of 2025.