Continental Divide

For other continental divides, see: continental divide. The Continental Divide or Great Divide is a ridge of mountains in North America and Central America which separates the major watershed that flows west into the Pacific Ocean from the ones that flow north into the Arctic Ocean and south-east into the Gulf of Mexico. Most of the divide follows the crest of the Rocky Mountains. This is a simplified view, however; many areas of North America drain internally.

The divide begins at Cape Prince of Wales in Alaska and heads southwards into the Yukon Territory and British Columbia in Canada, continuing south through Montana, Wyoming, Colorado, and New Mexico in the United States. It then goes further south into Mexico and Central America following the crest of the Sierra Madre Occidental.

The southern portion of the border between the Canadian provinces of British Columbia and Alberta is defined by the Continental Divide.

Triple Divide Peak in Glacier National Park in Montana forms the triple point at which waters flow to the Pacific, Atlantic and Arctic Oceans. (By another calculation, if the waters of Hudson's Bay are considered separate from the Arctic ocean a lesser triple divide is within the Columbia Icefield in British Columbia.)

The Continental Divide Trail follows the divide through the U.S. from the Mexican border to the Canadian border.

Exceptions

Many endorheic regions in North America complicate the simple view of east or west, "ocean-bound" water flow.

There is a portion of the divide that actually splits and goes around the Great Divide Basin in Wyoming, which, having no natural outlet except as groundwater, is neither in the Atlantic nor Pacific watersheds. North Two Ocean Creek in Wyoming forms another "hole", but one that flows into both oceans.

The Great Basin of the Western US, The Valley of Mexico and Bolson de Mapimi in Mexico, the Tularosa Basin in New Mexico and Texas, and the Salton Trough are examples of internally draining areas. In these cases, water often drains to low basins, where sedimentation and evaporation form salt lakes, playas, salt flats, and alkali flats.

On the Llano Estacado in Texas and New Mexico, many thousands of seasonal playa lakes form during wet months, an average of one per acre. This region is very flat, and water mostly evaporates before draining.

Zuni Salt Lake is one example of a larger, seasonal maar which does not drain to an ocean. There are a number of seasonal lakes of this sort in North America. In areas of karst topography (such as northern Florida), isolated drainages can also occur.

Additionally, although Panama's isthumus provides clear division between Atlantic and Pacific, the boundaries between the Atlantic and Arctic Oceans in Baffin Bay are not well defined, rendering the easternmost portion of this divide arbitrary.

External links

A detailed map of watersheds in North America
A detailed overview of isolated wetlands from the USFWS
Detailed article, maps, and boundary data from The National Atlas of the United States
Parting of the Waters: a creek that flows to two oceans

Mountain ranges of North America

Divisòria continental nord-americana | Nordamerikanische kontinentale Wasserscheide

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Exceptions

See also

External links