:'' This article is about the Atlantic/Pacific divide of North America. For continental divides in general, see
Continental divide. For the movie, see
Continental Divide (film)''

In this very simplified view, The Continental Divide is the border between the green and the red/blue areas
'Continental Divide' or 'Great Divide' is the name given to the
North American portion of the
mountainous
ridge which separates the
watersheds that drain into the
Pacific Ocean from, 1) those river systems which drain into the
Atlantic Ocean (including those which drain via the
Gulf of Mexico), and 2) along the northernmost reaches of the Divide, those river systems which drain into the
Arctic Ocean. A secondary, non-mountainous divide further separates other river systems that drain into the Arctic Ocean (including those which drain via
Hudson Bay,
James Bay, and
Ungava Bay) from those which drain into the Atlantic Ocean (including those which drain via the
Great Lakes and
Saint Lawrence Seaway).
The divide begins at
Cape Prince of Wales in
Alaska. It runs northeast-/eastward across the north of the state into the
Yukon Territory,
Canada, where it turns south and travels through
British Columbia (forming part of the B.C.-
Alberta boundary), in Canada; then through
Montana (forming part of the Montana-
Idaho boundary),
Wyoming,
Colorado, and
New Mexico, in the
United States; then along the crest of the
Sierra Madre Occidental through the
Mexican states of
Chihuahua,
Durango,
Zacatecas,
Aguascalientes,
Jalisco,
Guanajuato,
México and the
Distrito Federal,
Morelos,
Puebla,
Oaxaca, and
Chiapas; thence through southern
Guatemala, southwestern
Honduras, western
Nicaragua, and western/southwestern
Costa Rica, and southern
Panama.
The physical divide continues (though the name "Great Divide" does not) into
South America, where it follows the peaks of the
Andes Mountains, traversing western
Colombia, central
Ecuador, western and southwestern
Peru, and eastern
Chile (essentially conforming to the Chile-
Bolivia and Chile-
Argentina boundaries), southward to the southern end of
Patagonia and
Tierra del Fuego.
In North America,
Triple Divide Peak in
Glacier National Park, in Montana, is the point at which the three principal continental divides in North America converge. From this point, waters flow to the Pacific, the Atlantic and the Arctic Oceans. Another calculation, however, puts a lesser triple divide within the
Columbia Icefield in
Alberta, by separating
Hudson Bay (thus, the rivers that drain into it) from the Arctic Ocean.
The
Continental Divide Trail follows the divide through the U.S. from the
Mexican border to the
Canadian border. Also in the mid 80s two men named Jim and Corky Dickinson rode along the divide from Mexico to Canada on mules. The journey took 6 months and a week to complete. To this day they are the only two to attempt to do this using no vehicles, or any help of the sort. This trip has still not been matched.
Exceptions
Many
endorheic regions in North America complicate the simple view of east or west, "ocean-bound" water flow.
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.
The
Great Divide Basin in Wyoming has no natural outlet except as
groundwater, and hence it lies between the Atlantic and Pacific watersheds, being part of neither. Water from the
North Two Ocean Creek in Wyoming flows into both oceans.
Additionally, although
Panama's isthmus 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.
Images
See also
★
List of railroad crossings of the North American continental divide
★
Laurentia
★
Continental Divide Trail
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