The Continental Divide of the Americas is the principal, and largely mountainous, hydrological divide of the Americas. The Continental Divide extends from the Bering Strait to the Strait of Magellan, and separates the watersheds that drain into the Pacific Ocean from those river systems that drain into the Atlantic and Arctic Ocean, including those that drain into the Gulf of Mexico, the Caribbean Sea, and Hudson Bay.
The Canadian Rockies or Canadian Rocky Mountains, comprising both the Alberta Rockies and the British Columbian Rockies, is the Canadian segment of the North American Rocky Mountains. It is the easternmost part of the Canadian Cordillera, which is the northern segment of the North American Cordillera, the expansive system of interconnected mountain ranges between the Interior Plains and the Pacific Coast that runs northwest–southeast from central Alaska to the Isthmus of Tehuantepec in Mexico.
Lake Missoula was a prehistoric proglacial lake in western Montana that existed periodically at the end of the last ice age between 15,000 and 13,000 years ago. The lake measured about 7,770 square kilometres (3,000 sq mi) and contained about 2,100 cubic kilometres (500 cu mi) of water, half the volume of Lake Michigan.
The Clark Fork, or the Clark Fork of the Columbia River, is a river in the U.S. states of Montana and Idaho, approximately 310 miles (500 km) long. It is named after William Clark of the 1806 Lewis and Clark Expedition. The largest river by volume in Montana, it drains an extensive region of the Rocky Mountains in western Montana and northern Idaho in the watershed of the Columbia River. The river flows northwest through a long valley at the base of the Cabinet Mountains and empties into Lake Pend Oreille in the Idaho Panhandle. The Pend Oreille River in Idaho, Washington, and British Columbia, Canada which drains the lake to the Columbia in Washington, is sometimes included as part of the Clark Fork, giving it a total length of 479 miles (771 km), with a drainage area of 25,820 square miles (66,900 km2). In its upper 20 miles (32 km) in Montana near Butte, it is known as Silver Bow Creek. Interstate 90 follows much of the upper course of the river from Butte to Saint Regis. The highest point within the river's watershed is Mount Evans at 10,641 feet (3,243 m) in Deer Lodge County, Montana along the Continental Divide.
The Pend Oreille River is a tributary of the Columbia River, approximately 130 miles (209 km) long, in northern Idaho and northeastern Washington in the United States, as well as southeastern British Columbia in Canada. In its passage through British Columbia its name is spelled Pend-d'Oreille River. It drains a scenic area of the Rocky Mountains along the U.S.-Canada border on the east side of the Columbia. The river is sometimes defined as the lower part of the Clark Fork, which rises in western Montana. The river drains an area of 66,800 square kilometres (25,792 sq mi), mostly through the Clark Fork and its tributaries in western Montana and including a portion of the Flathead River in southeastern British Columbia. The full drainage basin of the river and its tributaries accounts for 43% of the entire Columbia River Basin above the confluence with the Columbia. The total area of the Pend Oreille basin is just under 10% of the entire 258,000-square-mile (670,000 km2) Columbia Basin. Box Canyon Dam is currently underway on a multimillion-dollar project for a fish ladder.
The Kootenay River or Kootenai River is a major river of the Northwest Plateau in southeastern British Columbia, Canada, and northern Montana and Idaho in the United States. It is one of the uppermost major tributaries of the Columbia River, the largest North American river that empties into the Pacific Ocean. The Kootenay River runs 781 kilometres (485 mi) from its headwaters in the Kootenay Ranges of the Canadian Rockies, flowing from British Columbia's East Kootenay region into northwestern Montana, then west into the northernmost Idaho Panhandle and returning to British Columbia in the West Kootenay region, where it joins the Columbia at Castlegar.
The Flathead River, in the northwestern part of the U.S. state of Montana, originates in the Canadian Rockies to the north of Glacier National Park and flows southwest into Flathead Lake, then after a journey of 158 miles (254 km), empties into the Clark Fork. The river is part of the Columbia River drainage basin, as the Clark Fork is a tributary of the Pend Oreille River, a Columbia River tributary. With a drainage basin extending over 8,795 square miles (22,780 km2) and an average discharge of 11,380 cubic feet per second (322 m3/s), the Flathead is the largest tributary of the Clark Fork and constitutes over half of its flow.
Lake McDonald is the largest lake in Glacier National Park. It is located at 48°35′N113°55′W in Flathead County in the U.S. state of Montana. Lake McDonald is approximately 10 miles (16 km) long, and over a mile (1.6 km) wide and 472 feet deep, filling a valley formed by a combination of erosion and glacial activity. Lake McDonald lies at an elevation of 3,153 feet (961 m) and is on the west side of the Continental Divide. Going-to-the-Sun Road parallels the lake along its southern shoreline. The surface area of the lake is 6,823 acres (27.6 km2).
Snow Dome is a mountain located on the Continental Divide in the Columbia Icefield, where the boundary of Banff National Park and Jasper National Park meets the border of Alberta and British Columbia in Canada. The summit's elevation is 3,456 m (11,339 ft).
The Hudson Bay drainage basin is the drainage basin in northern North America where surface water empties into the Hudson Bay and adjoining waters. Spanning an area of about 3,861,400 square kilometres (1,490,900 sq mi) and with a mean discharge of about 30,900 m3/s (1,090,000 cu ft/s), the basin is almost entirely within Canada. It encompasses parts of the Canadian Prairies, Central Canada, and Northern Canada. A small area of the basin is in the northern part of the Midwestern United States.
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 the Great Lakes-St. Lawrence watershed to the southeast.
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 connected to the open sea. Every continent on earth except Antarctica has at least one continental drainage divide; islands, even small ones like Killiniq Island on the Labrador Sea in Canada, may also host part of a continental divide or have their own island-spanning divide. The endpoints of a continental divide may be coastlines of gulfs, seas or oceans, the boundary of an endorheic basin, or another continental divide. One case, the Great Basin Divide, is a closed loop around an endorheic basin. The endpoints where a continental divide meets the coast are not always definite since the exact border between adjacent bodies of water is usually not clearly defined. The International Hydrographic Organization's publication Limits of Oceans and Seas defines exact boundaries of oceans, but it is not universally recognized. Where a continental divide meets an endorheic basin, such as the Great Divide Basin of Wyoming, the continental divide splits and encircles the basin. Where two divides intersect, they form a triple divide, or a tripoint, a junction where three watersheds meet.
Montana is one of the eight Mountain States, located in the north of the region known as the Western United States. It borders North Dakota and South Dakota to the east. Wyoming is to the south, Idaho is to the west and southwest, and the Canadian provinces of British Columbia, Alberta, and Saskatchewan are to the north, making it the only state to border three Canadian provinces.
The North Fork Flathead River is a 153-mile (246 km) river flowing through British Columbia, Canada, south into the U.S. state of Montana. It is one of the three primary forks of the Flathead River, the main inflow of Flathead Lake and a tributary of the Columbia River via the Clark Fork River and the Pend Oreille River. The river is sometimes considered the upper headwaters of the Flathead River, although the North Fork is its official name in the U.S. Other naming conventions for the river include Flathead River - North Fork, North Fork of Flathead River, and North Fork of the Flathead River.
The Middle Fork Flathead River is a 92-mile (148 km) river in western Montana in the United States, forming the southwestern boundary of Glacier National Park. Its drainage basin lies to the east of the South Fork Flathead River and the Hungry Horse Reservoir. Towns along the river include West Glacier, Nyack, Pinnacle, Essex, and Nimrod.
The Swan Range is a mountain range in western Montana in the United States. Its peaks typically rise to around 8,000 to 9,000 feet. The range is bounded by the South Fork Flathead River to the east, the Flathead River to the north and northwest, the Swan River to the west, and lie to the southwest of Glacier National Park, just south of the Canada–US border. It runs about 99 miles (159 km) from north-northwest to south-southeast. Major cities near the Swan Range include Kalispell and Bigfork to the northwest, and Seeley Lake on the south.
A lake bifurcation occurs when a lake has outflows into two different drainage basins. In this case, the drainage divide cannot be defined exactly, as it is situated in the middle of the lake.
Watersheds of North America are large drainage basins which drain to separate oceans, seas, gulfs, or endorheic basins. There are six generally recognized hydrological continental divides which divide the continent into seven principal drainage basins spanning three oceans and one endorheic basin. The basins are the Atlantic Seaboard basin, the Gulf of Mexico basin, the Great Lakes-St. Lawrence basin, the Pacific basin, the Arctic basin, the Hudson Bay basin, and the Great Basin. Together, the principal basins span the continent with the exception of numerous smaller endorheic basins.
A triple divide or triple watershed is a point on Earth's surface where three drainage basins meet. A triple divide results from the intersection of two drainage divides. Triple divides range from prominent mountain peaks to minor side peaks, down to simple slope changes on a ridge which are otherwise unremarkable. The elevation of a triple divide can be thousands of meters to barely above sea level. Triple divides are a common hydrographic feature of any terrain that has rivers, streams and/or lakes.
