Richelieu River

Richelieu River
Richelieu River at Saint-Marc-sur-Richelieu
Country	Canada, and appreciable parts of New York State and Vermont
Basin features
Main source	Lake Champlain
River mouth	Saint Lawrence River at Sorel
Basin size	23,720 km2 (9,160 sq mi)
Physical characteristics
Length	124 km (77 mi)
Discharge	Average rate: 330 m3/s (12,000 cu ft/s)

The Richelieu River takes its source in Lake Champlain, from which it flows to the north in the province of Quebec, Canada and empties into the St. Lawrence river. It was formerly known as the Iroquois River and the Chambly River. This river was a key route of water transport for cross-border trade between Canada and the United States, until the arrival of the railway in the mid-19th century.

Because of its strategic position between New France and New England, several military fortifications were erected on the course of the river. It served as a key pathway for several military tours and was the scene of several battles between the end of the 17th and early 19th centuries, first between the French and the Iroquois, then between the French and the English, during the regime of the New France and finally between the English and the Americans after 1760.

The Richelieu River has a drainage basin of 23,720 square kilometres (9,160 sq mi)² - including those of Lake Champlain 19,925 km² (7,693 sq mi) and Missisquoi Bay (1 289 km²). Of this, 19,600 km² (7,600 sq mi) are in the United States, originating in the western slopes of the Green Mountains and the eastern slopes of the Adirondack Mountains of New York State. The Champlain Valley makes up most of the drainage basin.

With a length of 124 km (77 mi), the Richelieu River takes its source at the north end of Lake Champlain on the border between Canada (Quebec) and the United States (Vermont and New York state). The river flows through many towns: Lacolle, Île aux Noix, Saint-Jean-sur-Richelieu, Chambly, Beloeil, Saint-Charles-sur-Richelieu, Saint-Denis-sur-Richelieu, Saint-Ours and Sorel-Tracy where the river empties into the Saint Lawrence River, around 40 km northeast of Montreal and southwest of Quebec City.