Farmington River

The Farmington River is a river, 46.7 miles in length along its main stem, located in northwest Connecticut with major tributaries extending into southwest Massachusetts. The longest route of the river, from the origin of its West Branch, is 80.4 miles long, making it the Connecticut River's longest tributary by 2.3 miles over the major river directly to its north, the Westfield River. The Farmington River's watershed covers 609 square miles . Historically, the river played an important role in small-scale manufacturing in towns along its course, but it is now mainly used for recreation and drinking water.

Headwaters for the two main branches of the Farmington River, the East Branch and West Branch, are found in southwestern Massachusetts, though only one, the West Branch, officially begins north of the Connecticut border. The West Branch begins at the outlet of Hayden Pond in Otis, Massachusetts. The East Branch begins in Hartland, Connecticut at the confluence of Pond, Hubbard and Valley Brooks. However, this branch has been impounded along the first 11 miles of its course to form the Barkhamsted Reservoir and Lake McDonough; it does not assume a river-like appearance until it exits Lake McDonough in New Hartford, Connecticut. The East Branch and West Branch join in New Hartford, Connecticut, one mile south of the lake. Upper reaches of the river generally flow southward, but the river turns northward in Farmington, Connecticut and runs mostly north and east until it flows into the Connecticut River in Windsor.

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