The Saint Lawrence River Divide is a

continental divide A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not ...

in central and eastern

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

that separates the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes spanning the Canada–United States border. The five lakes are Lake Superior, Superior, Lake Michigan, Michigan, Lake Huron, H ...

St. Lawrence River The St. Lawrence River (, ) is a large international river in the middle latitudes of North America connecting the Great Lakes to the North Atlantic Ocean. Its waters flow in a northeasterly direction from Lake Ontario to the Gulf of St. Lawren ...

Basin from the southerly

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

watersheds. Water, including rainfall and snowfall, lakes, rivers and streams, north and west of the divide, drains into the Gulf of St. Lawrence or the

Labrador Sea The Labrador Sea (; ) is an arm of the North Atlantic Ocean between the Labrador Peninsula and Greenland. The sea is flanked by continental shelf, continental shelves to the southwest, northwest, and northeast. It connects to the north with Baffi ...

; water south and east of the divide drains into the Atlantic Ocean (east of the

Eastern Continental Divide The Eastern Continental Divide, Eastern Divide or Appalachian Divide is a drainage divide, hydrological divide in eastern North America that separates the easterly Atlantic Seaboard drainage basin, watershed from the westerly Gulf of Mexico wat ...

, ECD) or

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

(west of the ECD). The divide is one of six continental divides in North America that demarcate several watersheds that flow to different gulfs, seas or oceans.

Course

West of the triple divide

The divide has its origin at ‘ Hill of Three Waters’ triple divide on the

Laurentian Divide The Laurentian Divide also called the Northern Divide and locally the '' height of land'', is a continental divide in central North America that separates the Hudson Bay watershed to the north from the Gulf of Mexico watershed to the south and ...

approx. 2 miles north of

Hibbing, Minnesota Hibbing is a city in St. Louis County, Minnesota, Saint Louis County, Minnesota, United States. The population was 16,214 at the 2020 United States census, 2020 census. The city was built on mining the rich iron ore of the Mesabi Iron Range an ...

. It follows the western boundary of the Saint Louis River watershed, and then winds through the

Northern Highland The Northern Highland is a geographical region in the East North Central States, north central United States covering much of the northern territory of the state of Wisconsin. The region stretches from the state border with Minnesota in the wes ...

Wisconsin Wisconsin ( ) is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest of the United States. It borders Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michig ...

south of the shore of

Lake Superior Lake Superior is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. Lake Michigan–Huron has a larger combined surface area than Superior, but is normally considered tw ...

. It then follows the boundary between the

Wisconsin River The Wisconsin River is the longest river in the U.S. state of Wisconsin, at approximately 430 miles (692 km) long. As a tributary of the Mississippi River, it is part of the Mississippi River System. The river's name was first recorded in 1673 b ...

and Fox River watersheds. In Illinois and Indiana, it follows the Valparaiso Moraine separating the watershed of

Lake Michigan Lake Michigan ( ) is one of the five Great Lakes of North America. It is the second-largest of the Great Lakes by volume () and depth () after Lake Superior and the third-largest by surface area (), after Lake Superior and Lake Huron. To the ...

to the north from that of the

Illinois River The Illinois River () is a principal tributary of the Mississippi River at approximately in length. Located in the U.S. state of Illinois, the river has a drainage basin of . The Illinois River begins with the confluence of the Des Plaines ...

to the south. It passes through the heart of the city of

Chicago Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...

. Between roughly

South Bend South Bend is a city in St. Joseph County, Indiana, United States, and its county seat. It lies along the St. Joseph River (Lake Michigan), St. Joseph River near its southernmost bend, from which it derives its name. It is the List of cities in ...

and

Fort Wayne Fort Wayne is a city in Allen County, Indiana, United States, and its county seat. Located in northeastern Indiana, the city is west of the Ohio border and south of the Michigan border. The city's population was 263,886 at the 2020 United S ...

the divide zig-zags among hilly terrain. After that it follows the Wabash Moraine in western

Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...

, separating the first the watersheds of the

Maumee River The Maumee River (pronounced ) (; ) is a river running in the Midwestern United States from northeastern Indiana into northwestern Ohio and Lake Erie. It is formed at the confluence of the St. Joseph River (Maumee River), St. Joseph and St. Mar ...

to the north and

Wabash River The Wabash River () is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed May 13, 2011 river that drains most of the state of Indiana, and a significant part of Illinois, in the United ...

to the south, and later the Sandusky River to the north from the

Scioto River The Scioto River ( ) is a river in central and southern Ohio more than in length. It rises in Hardin County, Ohio, Hardin County just north of Roundhead, Ohio, flows through Columbus, Ohio, where it collects its largest tributary, the Olent ...

to the south. The divide then generally parallels the Portage Escarpment near the southern shore of

Lake Erie Lake Erie ( ) is the fourth-largest lake by surface area of the five Great Lakes in North America and the eleventh-largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and also has the shortest avera ...

through eastern Ohio,

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

, and western

New York New York most commonly refers to: * New York (state), a state in the northeastern United States * New York City, the most populous city in the United States, located in the state of New York New York may also refer to: Places United Kingdom * ...

. This portion's northern watersheds include several smaller rivers that drain directly to Lake Erie, the largest of which is the

Cuyahoga River The Cuyahoga River (see ) is a river located in Northeast Ohio that bisects the City of Cleveland and feeds into Lake Erie. As Cleveland emerged as a major manufacturing center, the river became heavily affected by industrial pollution, so mu ...

; the southern watersheds are the

Muskingum River The Muskingum River ( ; ) is a tributary of the Ohio River, approximately long, in southeastern Ohio in the United States. An important commercial route in the 19th century, it flows generally southward through the eastern hill country of Ohio ...

, Beaver River, and

Allegheny River The Allegheny River ( ; ; ) is a tributary of the Ohio River that is located in western Pennsylvania and New York (state), New York in the United States. It runs from its headwaters just below the middle of Pennsylvania's northern border, nor ...

. After passing around Chautauqua Lake, which is in the Allegheny River watershed, the divide turns away from Lake Erie and it crosses into the

Allegheny Plateau The Allegheny Plateau ( ) is a large dissected plateau area of the Appalachian Mountains in western and central New York, northern and western Pennsylvania, northern and western West Virginia, and eastern Ohio. It is divided into the unglacia ...

region. It follows the boundary of Cattaraugus Creek and then the

Genesee River The Genesee River ( ) is a tributary of Lake Ontario flowing northward through the Twin Tiers of Pennsylvania and New York (state), New York in the United States. The river contains several waterfalls in New York at Letchworth State Park and Roch ...

basins to the north, while continuing to drain to the Allegheny River to the south. After reentering Pennsylvania, the St. Lawrence River divide meets the triple divide at the northern end of the

East of the triple divide

Through central

, the divide separates the Oswego River watershed, which contains most of the

Finger Lakes The Finger Lakes are a group of eleven long, narrow, roughly north–south lakes located directly south of Lake Ontario in an area called the ''Finger Lakes region'' in New York (state), New York, in the United States. This region straddles th ...

region, to the north from the

Susquehanna River The Susquehanna River ( ; Unami language, Lenape: ) is a major river located in the Mid-Atlantic (United States), Mid-Atlantic region of the United States, crossing three lower Northeastern United States, Northeast states (New York, Pennsylvani ...

basin to the south. The divide then follows the boundary of the

Hudson River The Hudson River, historically the North River, is a river that flows from north to south largely through eastern New York (state), New York state. It originates in the Adirondack Mountains at Henderson Lake (New York), Henderson Lake in the ...

watershed to the south through the

Adirondacks The Adirondack Mountains ( ) are a massif of mountains in Northeastern New York (state), New York which form a circular dome approximately wide and covering about . The region contains more than 100 peaks, including Mount Marcy, which is the hi ...

, dipping briefly south of Lake George and

Lake Champlain Lake Champlain ( ; , ) is a natural freshwater lake in North America. It mostly lies between the U.S. states of New York (state), New York and Vermont, but also extends north into the Canadian province of Quebec. The cities of Burlington, Ve ...

before following the northern boundary of the

Connecticut River The Connecticut River is the longest river in the New England region of the United States, flowing roughly southward for through four states. It rises 300 yards (270 m) south of the U.S. border with Quebec, Canada, and discharges into Long Isl ...

watershed. For its next stretch, the divide follows the boundary of the Saint John River watershed to the south. The divides becomes the international border between

Maine Maine ( ) is a U.S. state, state in the New England region of the United States, and the northeasternmost state in the Contiguous United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Provinces and ...

and

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

between the headwaters of Halls Stream and the Southwest Branch Saint John River. The divide then continues into the Notre-Dame Mountains in Quebec, then turns southeasterly through central

New Brunswick New Brunswick is a Provinces and Territories of Canada, province of Canada, bordering Quebec to the north, Nova Scotia to the east, the Gulf of Saint Lawrence to the northeast, the Bay of Fundy to the southeast, and the U.S. state of Maine to ...

. From there, the divide borders the

Petitcodiac River The Petitcodiac River () is a river located in south-eastern New Brunswick, Canada. Local tourist businesses often refer to it as the "chocolate river" due to its distinctive brown mud floor and brown waters. Stretching across a meander length o ...

basin, crosses through the

Isthmus of Chignecto The Isthmus of Chignecto is an isthmus bordering the Maritime provinces of New Brunswick and Nova Scotia that connects the Nova Scotia peninsula with North America. The isthmus separates the waters of Chignecto Bay, a sub-basin of the Bay of ...

, and runs easterly along the

Cobequid Mountains The Cobequid Mountains, also sometimes referred to as the Cobequid Hills, is a Canadian mountain range located in Nova Scotia in the Nova Scotia peninsula, mainland portion of the province. Geologic history Geologically, the Cobequid Mountains are ...

along the northern coast of

Nova Scotia Nova Scotia is a Provinces and territories of Canada, province of Canada, located on its east coast. It is one of the three Maritime Canada, Maritime provinces and Population of Canada by province and territory, most populous province in Atlan ...

and eventually to Cape Canso.

Hydrology

As the divide is generally in close proximity to each of the Great Lakes to the north, the rivers on this side of the divide are generally short. To the southwest, there are broader watersheds that are tributaries of the

Upper Mississippi River The Upper Mississippi River is the portion of the Mississippi River upstream of St. Louis, Missouri, United States, a city at the confluence of its main tributary, the Missouri River. Historically, it may refer to the area above the Arkansa ...

and the

Ohio River The Ohio River () is a river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing in a southwesterly direction from Pittsburgh, Pennsylvania, to its river mouth, mouth on the Mississippi Riv ...

that ultimately drain to the

. To the southeast are several major river watersheds that drain directly to the

Canals

Four canals cross the divide: The Champlain Canal connects

to the

watershed. The

Erie Canal The Erie Canal is a historic canal in upstate New York that runs east–west between the Hudson River and Lake Erie. Completed in 1825, the canal was the first navigability, navigable waterway connecting the Atlantic Ocean to the Great Lakes, ...

connects

to the

watershed. The

Chicago Sanitary and Ship Canal The Chicago Sanitary and Ship Canal, historically known as the Chicago Drainage Canal, is a canal system that connects the Chicago River to the Des Plaines River. It reverses the direction of the Main Stem and the South Branch of the Chicago ...

crosses the Chicago Portage and connects

to the

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

watershed. The Portage Canal connects the Fox River to the

Portage, Wisconsin Portage is a city in Columbia County, Wisconsin, United States, and its county seat. The population was 10,581 at the 2020 census, making it the largest city in Columbia County. It is part of the Madison metropolitan area. Portage was named for ...

. Historically there were additional canals, e.g., the

Ohio and Erie Canal The Ohio and Erie Canal was a canal constructed during the 1820s and early 1830s in Ohio. It connected Akron, Ohio, Akron with the Cuyahoga River near its outlet on Lake Erie in Cleveland, Ohio, Cleveland, and a few years later, with the Ohio ...

, but most of these are no longer in operation.

Locations

References

{{DEFAULTSORT:Saint Lawrence River Divide Geography of the United States Drainage divides Drainage basins of North America Saint Lawrence River