History of the Housatonic Valley
The Mohican family of the Algonkin Indians, who came from New York west over the Taconic mountains, were the first valley settlers. The six main tribes migrated south as follows: the Weataugs settled in Salisbury; Weantinocks in New Milford; Paugassets in Derby; Potatucks in Shelton; Pequannocks in Bridgeport; and, Wepawaugs in Milford. The Indians named the river "usi-a-di-en-uk" which meant "beyond the mountain place."
The river was sometimes known as "Potatuck," or the "Great River," until the 18th century. A large portion of the river basin was developed for agriculture in Colonial times. Water power played a prominent role in 19th century industrial development, and remnants of dams, mill races and iron ore furnaces can still be seen today. Northeast Utilities operates five hydroelectric facilities on the river today. Dams at three of these facilities - the Shepaug, Stevenson and Derby - form a chain of lakes - Lake Lillinonah, Lake Zoar and Lake Housatonic, from New Milford south to Shelton. Much of the upper section of the river in Massachusetts is still in agricultural use, however, past industrial discharges of PCBs (polychlorinated biphenyls) into the river has created water quality problems. PCBs still remain in the river's sediments from Massachusetts to the Stevenson Dam in Connecticut. These synthetic organic chemicals can persist for decades and are a cause for concern and continued action.
Further down in the valley, in the areas of New Milford and Brookfield, tobacco farms flourished until the surge of 20th century development. South of Derby, industrial development, including steel mills and heavy manufacturing, characterizes the river. This stretch is also a tidal estuary, which supports a number of critical habitats for rare plants and animals and is a significant contributor to Connecticut's shellfish population. The Housatonic estuary is the most consistent producer of seed oysters in the northeast as a public oyster bed, and generates over one-third of all oyster seed available to the state shellfish industry.