Continental Divide of the Americas
The Continental Divide of the Americas (also known as the Great Divide, the Western Divide or simply the Continental Divide;
Although there are many other hydrological divides in the Americas, the Continental Divide is by far the most prominent of these because it tends to follow a line of high peaks along the main ranges of the Rocky Mountains and Andes, at a generally much higher elevation than the other hydrological divisions.
Geography
Beginning at the westernmost point of the Americas, Cape Prince of Wales, just south of the Arctic Circle, the Continental Divide's geographic path runs through Arctic Alaska, where it reaches its more northerly point close to the U.S.-Canada border near the Beaufort Sea. The Divide zig-zags southwardly over Yukon, and forms part of the boundary between Yukon and the Northwest Territories in the Mackenzie Mountains. It then proceeds through the Northern British Columbia Interior via the Cassiar Mountains, Omineca Mountains and northern Nechako Plateau to Summit Lake, north of the city of Prince George and just south of the community of McLeod Lake. From there the Divide traverses the McGregor Plateau to the spine of the Rockies, following the crest of the Canadian Rockies southeast to the 120th meridian west, from there forming the boundary between southern British Columbia and southern Alberta.
The Divide crosses into the United States in northwestern Montana, at the boundary between Waterton Lakes National Park and Glacier National Park. In Canada, it forms the western boundary of Waterton Lakes National Park, and in the US bisects Glacier National Park. Further south, the Divide forms the backbone of the Rocky Mountain Front (Front Range) in the Bob Marshall Wilderness, heads south towards Helena and Butte, then west past the namesake community of Divide, Montana, through the Anaconda-Pintler Wilderness to the Bitterroot Range, where it forms the eastern third of the state boundary between Idaho and Montana. The Divide crosses into Wyoming within Yellowstone National Park and continues southeast around the Great Divide Basin, through the Sierra Madre Range into Colorado where it reaches its highest point in North America at the summit of Grays Peak at 4,352 metres (14,278 ft).[citation needed] It crosses US Hwy 160 in southwestern Colorado at Wolf Creek Pass, where a line symbolizes the division. The Divide then proceeds south into western New Mexico, passing along the western boundary of the endorheic Plains of San Agustin. Although the Divide represents the height of land between watersheds, it does not always follow the highest ranges/peaks within each state or province.
In
The Divide continues into
Additional divides
The
Triple points
Triple Divide Peak in Glacier National Park, Montana, is the point where two of the principal continental divides in North America converge, the primary Continental Divide and the Northern or Laurentian Divide. From this point, waters flow to the Pacific Ocean, the Atlantic Ocean via the Gulf of Mexico, and the Arctic Ocean via Hudson Bay. Most geographers, geologists, meteorologists, and oceanographers consider this point the hydrological apex of North America, as Hudson Bay is generally considered part of the Arctic Ocean. For example, the International Hydrographic Organization (in its current unapproved working edition only[2] of Limits of Oceans and Seas) defines the Hudson Bay, with its outlet extending from 62.5 to 66.5 degrees north (just a few miles south of the Arctic Circle) as being part of the Arctic Ocean, specifically "Arctic Ocean Subdivision 9.11."
This hydrological apex of North America status of Triple Divide Peak is the main reason behind the designation of Waterton-Glacier International Peace Park as the "Crown of the Continent" of North America.[3] The summit of the peak is the world's only oceanic triple divide point.[4] Discounting Antarctica and its ice sheets, only one other continent (Asia) borders three oceans, but the inward-draining Endorheic basin area of Central Asia from western China to the Aral and Caspian Seas is so vast that any Arctic and Indian Ocean tributaries are never within proximity of each other.[4] Thus, North America's status of having a single location draining into three oceans is unique in the world.
Sources differ, however, on whether Hudson Bay, entirely south of the Arctic Circle, is part of the Atlantic or Arctic Ocean.[5] Hudson Bay's water budget connects to the Atlantic more than to the Arctic Ocean.[6] The channels to the north of Hudson Bay are largely cut off by Baffin Island from the Arctic, so much of the water that enters it mixes with the Atlantic to the east via Hudson Strait rather than north into the Arctic. The result is that most of the ice flowing down the Saskatchewan Glacier eventually ends up as water in the Atlantic Ocean.[7][8]
If Hudson Bay is considered part of the Atlantic, then the triple point is at an unimportant-looking, permanently snow and ice covered hump on the border between Alberta and British Columbia, on the southern slope of Snow Dome at 3,456 metres (11,300 ft). The exact location of this potential triple point is somewhat indeterminate because the Columbia Icefield and the snow on top of it shifts from year to year. The snow that falls on it (about 10 metres (33 ft) per year) does not actually flow downhill as water, but creeps downhill in the form of glacial ice. That ice flows down the Athabasca Glacier to the Arctic Ocean via the Athabasca and Mackenzie rivers. Ice flowing west goes to the Pacific Ocean via Bryce Creek and the Bush and Columbia Rivers. Ice flowing down the Saskatchewan Glacier goes via the North Saskatchewan, Saskatchewan, and Nelson rivers into Hudson Bay.[9]
While Triple Divide Peak (or, alternatively, Snow Dome) is the world's only oceanic triple divide, there are secondary triple divide points wherever any two continental divides meet. North America has five major drainage systems: into the Pacific, Atlantic and Arctic oceans, plus Hudson Bay and the Gulf of Mexico. Other sources such as the
Hiking trail
The
Exceptions
Many
Another rare exception occurs when a stream near a divide splits and flows in both directions, or a lake straddling the divide overflows in both directions. Examples of these are, respectively,
Several small lakes along the Divide in the Rocky Mountains between Alberta and British Columbia flow into both provinces and thus into both the Arctic and Pacific Oceans. An example is the "Committee's Punch Bowl", a small lake located in the Athabasca Pass.[a]
The
See also
Continental divides
- Continental divide
- Eastern Continental Divide
- Great Basin Divide
- Laurentian Divide (Northern Divide)
- Saint Lawrence River Divide
- Triple divide
- American Cordillera
- Continental Divide Trail
- Cromwell Dixon
- Great Divide Mountain Bike Route
- Great Divide Trail
- Laurentia
- Lewis and Clark
- List of railroad crossings of the North American continental divide
Note
- George Simpson, governor of the Hudson's Bay Company, while touring his vast Canadian fur-trading empire in 1825. According to historical sources, "The small circular basin of water at the summit, twenty yards in diameter, is dignified with the name of the 'Committee's Punch Bowl' in honour of which the Governor treated them (his fur traders) to a bottle of wine as they had 'neither time nor convenience to make a bowl of punch, although a glass of it would have been acceptable.'" The reference is to the governing committee of the Hudson's Bay Company in London, England.[13]
References
- ISBN 9781911082026.
- ^ "IHO Publication S-23 Limits of Oceans and Seas; Chapter 9: Arctic Ocean". International Hydrographic Organization. 2002. Archived from the original on 2014-02-02. Retrieved 2017-07-01.
- ^ "State of Flathead Lake". University of Montana Flathead Lake Biological Station. Retrieved 2015-09-28.
- ^ a b "Ocean Triple Divide Points". Peakbagger.com. Retrieved 2017-07-01.
- ISBN 978-1-897425-57-2.
- ISBN 978-0-7923-6439-9. Retrieved 26 November 2010.
- ^ Timmer, Henry (2006). "Snow Dome - The Hydrological Apex of North America". Snow Dome. climbwild.net. Archived from the original on 2007-10-25. Retrieved 2007-12-28.
- ^ Timmer, Henry. "The Columbia Icefield". climbwild.net. Archived from the original on 2014-08-10. Retrieved 2014-07-30.
- ^ "Snow Dome-South Slope, British Columbia". Peakbagger. Retrieved 2015-09-28.
- ^ monica driscollian rivers atlas (2006). "Minnesota Rivers Map". Minnesota State Map Collection. Geology.com. Retrieved 2007-12-29.
- ^ Gonzalez, Mark A. (2002). "Continental Divides in North Dakota and North America" (PDF). NGDS Newsletter. North Dakota Geological Survey. Archived from the original (PDF) on 2013-01-17. Retrieved 2007-12-29.
- ISBN 0-921102-79-8. Archived from the originalon 2016-03-16. Retrieved 2010-04-08.
- ^ GeoBC (2013). "Committee Punch Bowl". gov.bc.ca. Province of British Columbia. Retrieved 2014-09-29.
External links
- A detailed map of watersheds in North America
- A detailed overview of isolated wetlands from the USFWS Archived 2006-05-15 at the Wayback Machine
- 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
- U.S. Geological Survey Geographic Names Information System: Continental Divide (New Mexico, Colorado, Wyoming, Idaho, Montana)
- U.S. Geological Survey Geographic Names Information System: Continental Divide (Alaska)