St. Lawrence River

The St. Lawrence River is a large international river in the middle latitudes of North America connecting the Great Lakes with the North Atlantic Ocean. Its waters flow in a northeasterly direction from Lake Ontario to the Gulf of St. Lawrence, traversing Ontario and Quebec in Canada and New York in the United States. A portion of the river demarcates the Canada–United States border.
As the primary drainage outflow of the Great Lakes Basin, the St. Lawrence has the second-highest discharge of any river in North America and the 16th-highest in the world. The estuary of the St. Lawrence is often cited by scientists as the largest in the world. Significant natural landmarks of the river and estuary include the 1,864 river islands of the Thousand Islands, the endangered whales of Saguenay–St. Lawrence Marine Park, and the limestone monoliths of the Mingan Archipelago.
Long a transportation route to Indigenous peoples, the St. Lawrence River has played a key role in the history of Canada and in the development of cities such as Montreal and Quebec City. The river remains an important shipping route as the backbone of the St. Lawrence Seaway, a lock and canal system that enables world marine traffic to access the inland ports of the Great Lakes Waterway.

Etymology

The river has historically been given a variety of different names by local First Nations. Beginning in the 16th century, French explorers visited what is now Canada and gave the river names such as the Grand fleuve de Hochelaga and the Grande rivière du Canada, where fleuve and rivière are two French words.
The river's present name has been used since 1604 when it was recorded on a map by Samuel de Champlain. Champlain opted for the names Grande riviere de sainct Laurens and Fleuve sainct Laurens in his writings, supplanting the earlier names. In contemporary French, the name is rendered as the fleuve Saint-Laurent. The name Saint-Laurent was originally applied to the eponymous bay by Jacques Cartier upon his arrival into the region on the 10th of August feast day for Saint Lawrence in 1535.
Indigenous people use the following names:

Innu-aimun, the language of Nitassinan, refer to it as Wepistukujaw Sipo/''Wepìstùkwiyaht sīpu.
the Abenaki call it Moliantegok/Moliantekw, Kchitegw/Ktsitekw/Gicitegw, or Oss8genaizibo/Ws8genaisibo/Wsogenaisibo.
in Mohawk language it is Roiatatokenti, Raoteniateara, Ken’tarókwen, or Kaniatarowanénhne.
Tuscarora people call it Kahnawáˀkye or Kaniatarowanenneh.
Algonquin people call it "the Walking Path" or Magtogoek, or Kitcikanii sipi, the "Large Water River".
the Wendat Nation call it Lada8anna or Laooendaooena'.
the Atikamekw of Nitaskinan refer to it as Micta sipi''.
Geography

Marine weather

In winter, the St. Lawrence River begins producing ice in December between Montreal and Quebec City. The prevailing winds and currents push this ice towards the estuary, and it reaches the east of Les Méchins at the end of December. Ice covers the entire Gulf of St. Lawrence in January and February.
Ice helps navigation by preventing the formation of waves, and therefore spray, and prevents the icing of ships.

Watershed

With the draining of the Champlain Sea, due to a rebounding continent from the Last Glacial Maximum, the St. Lawrence River was formed. The Champlain Sea lasted from about 13,000 years ago to about 10,000 years ago and was continuously shrinking during that time, a process that continues today. The head of the St. Lawrence River, near Lake Ontario, is home to the Thousand Islands.
Today, the St. Lawrence River begins at the outflow of Lake Ontario and flows adjacent to Cape Vincent, Gananoque, Clayton, Alexandria Bay, Brockville, Morristown, Ogdensburg, Massena, Cornwall, Montreal, Trois-Rivières, and Quebec City before draining into the Gulf of St. Lawrence, often given as the largest estuary in the world. The estuary begins at the eastern tip of Île d'Orléans, just downstream from Quebec City. The river becomes tidal around Quebec City.
The St. Lawrence River runs from the farthest headwater to the mouth and from the outflow of Lake Ontario. These numbers include the estuary; without the estuary, the length from Lake Ontario is c. 500 km. The farthest headwater is the North River in the Mesabi Range at Hibbing, Minnesota. Its drainage area, which includes the Great Lakes, the world's largest system of freshwater lakes, is, of which is in Canada and is in the United States. The basin covers parts of Ontario and Quebec in Canada, parts of Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, New York, Vermont, and nearly the entirety of the state of Michigan in the United States. The average discharge below the Saguenay River is. At Quebec City, it is. The average discharge at the river's source, the outflow of Lake Ontario, is.
The St. Lawrence River includes Lake Saint Francis at Salaberry-de-Valleyfield, Lake Saint-Louis south of Montreal and Lake Saint Pierre east of Montreal. It encompasses four archipelagoes: the Thousand Islands chain near Alexandria Bay, New York and Kingston, Ontario; the Hochelaga Archipelago, including the Island of Montreal and Île Jésus ; the Lake St. Pierre Archipelago and the smaller Mingan Archipelago. Other islands include Île d'Orléans near Quebec City and Anticosti Island north of the Gaspé. It is the second-longest river in Canada.
Lake Champlain and the Ottawa, Richelieu, Saint-Maurice, Saint-François, Chaudière and Saguenay rivers drain into the St. Lawrence.
The St. Lawrence River is in a seismically active zone where fault reactivation is believed to occur along late Proterozoic to early Paleozoic normal faults related to the opening of the Iapetus Ocean. The faults in the area are rift-related and comprise the Saint Lawrence rift system.
According to the United States Geological Survey, the St. Lawrence Valley is a physiographic province of the larger Appalachian division, containing the Champlain section. However, in Canada, where most of the valley is, it is instead considered part of a distinct St. Lawrence Lowlands physiographic division, and not part of the Appalachian division.

Tributaries

The St. Lawrence River and the largest tributaries of the Great Lakes.
The St. Lawrence River tributaries are listed upstream from the mouth. The major tributaries of the inter-lake sections are also shown, as well as the major rivers that flow into the Great Lakes. Great Lakes tributaries are listed in alphabetical order.
The list includes all tributaries with a drainage area of at least 1,000 square kilometres and an average flow of more than 10 cubic metres per second.

Discharge

Biodiversity

The diversity of the St. Lawrence River includes:

19 species of marine mammals
More than 230 species of birds
Nearly 35 species of amphibians and reptiles
200 species of freshwater and saltwater fish
2200 invertebrates in the estuary and its gulf
Nearly 2000 vascular plants
Marine mammals

Large marine mammals travel in all the seas of the earth, the research and observations of these giants concern fishermen and shipping industry, exercise a fascination and a keen interest for laymen and, subjects of endless studies for scientists from Quebec, Canada and around the world.
Thirteen species of cetaceans frequent the waters of the estuary and the Gulf of St. Lawrence:

First Nations

Flowing through and adjacent to numerous Indigenous homelands, the river was a primary thoroughfare for many peoples. Beginning in Dawnland at the Gulf of St. Lawrence, the river borders Mi'kma'ki in the South, and Nitassinan in the North, the national territory of the Innu people. On the south shore beyond the Mi'kmaw district of Gespe'gewa'ki, the river passes Wolastokuk, Pαnawαhpskewahki, and Ndakinna. Continuing, the river passes through the former country of the St. Lawrence Iroquois and then three of the six homelands of the Haudenosaunee: the Mohawk or Kanienʼkehá꞉ka, the Oneida or Onyota'a:ka, and the Onondaga or Onöñda’gaga’.
In the early 17th century, the Wendat Nation migrated from their original country of Huronia to what is now known as Nionwentsïo centred around Wendake. Nionwentsïo occupies both the north and south shores of the river, overlapping with Nitassinan and the more western Wabanaki or Dawnland countries. Adjacent on the north shore is the Atikamekw territorial homeland of Nitaskinan and, upstream, the further reaches of Anishinaabewaki, specifically the homelands of the Algonquin and Mississauga Nations.

European exploration

The Norse explored the Gulf of St. Lawrence in the 11th century and were followed by fifteenth- and early sixteenth-century European mariners, such as John Cabot, and the brothers Gaspar and Miguel Corte-Real. The first European explorer known to have sailed up the St. Lawrence River itself was Jacques Cartier. At that time, the land along the river described as "about two leagues, a mountain as tall as a heap of wheat" was inhabited by the St. Lawrence Iroquoians. During Cartier's second voyage in 1535, because Cartier arrived in the estuary on Saint Lawrence's feast day 10 August, he named it the Gulf of Saint Lawrence.
The St. Lawrence River is today partly within the U.S. and as such is that country's sixth oldest surviving European place-name.