Americas

=== Hydrology ===
With coastal mountains and interior plains, the Americas have several large [[river basin]]s that drain the continents. The largest river basin in North America is that of the [[Mississippi River|Mississippi]], covering the second largest [[Drainage basin|watershed]] on the planet.<ref>{{cite web|url=http://biology.usgs.gov/s+t/SNT/noframe/ms137.htm |title=Mississippi River |url-status=dead |archive-url=https://web.archive.org/web/20070715014306/http://biology.usgs.gov/s%2Bt/SNT/noframe/ms137.htm |archive-date=July 15, 2007 }}</ref> The Mississippi-Missouri river system drains most of 31 states of the U.S., most of the [[Great Plains]], and large areas between the Rocky and Appalachian mountains. This river is the [[List of rivers by length|fourth longest in the world]] and [[List of rivers by discharge|tenth most powerful in the world]].

In North America, to the east of the [[Appalachian Mountains]], there are no major rivers but rather a series of rivers and streams that flow east with their terminus in the Atlantic Ocean, such as the [[Hudson River]], [[Saint John River (Bay of Fundy)|Saint John River]], and [[Savannah River]]. A similar instance arises with central Canadian rivers that drain into [[Hudson Bay]]; the largest being the [[Churchill River (Hudson Bay)|Churchill River]]. On the west coast of North America, the main rivers are the [[Colorado River]], [[Columbia River]], [[Yukon River]], [[Fraser River]], and [[Sacramento River]].

The Colorado River drains much of the [[Southern Rockies]] and parts of the [[Basin and Range Province]]. The river flows approximately {{convert|1450|mi|km|sp=us}} into the [[Gulf of California]],<ref name=largest>{{cite web |last= Kammerer |first= J.C. |title= Largest Rivers in the United States |url= http://pubs.usgs.gov/of/1987/ofr87-242/ |publisher= United States Geological Survey |access-date=July 2, 2010}}</ref> during which over time it has carved out natural phenomena such as the [[Grand Canyon]] and created phenomena such as the [[Salton Sea]]. The Columbia is a large river, {{convert|1243|mi|km}} long, in central western North America and is the most powerful river on the West Coast of the Americas. In the far northwest of North America, the Yukon drains much of the Alaskan peninsula and flows {{convert|1980|mi|km}}<ref>{{cite web |url=http://www.yukoninfo.com/yukonriver/ |title=Yukoninfo.com |publisher=Yukoninfo.com |access-date=January 30, 2012 |archive-url=https://web.archive.org/web/20131024100547/http://www.yukoninfo.com/yukonriver/ |archive-date=October 24, 2013 |url-status=dead }}</ref> from parts of Yukon and the Northwest Territory to the Pacific. Draining to the Arctic Ocean of Canada, the [[Mackenzie River]] drains waters from the Arctic Great Lakes of Arctic Canada, as opposed to the Saint-Lawrence River that drains the Great Lakes of Southern Canada into the Atlantic Ocean. The Mackenzie River is the largest in Canada and drains {{convert|1805200|km2|mi2|sp=us}}.<ref>{{cite encyclopedia|url=https://www.britannica.com/eb/article-9110728 |title=Mackenzie River |encyclopedia=Encyclopædia Britannica |access-date=September 8, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20081118141110/https://www.britannica.com/eb/article-9110728 |archive-date=November 18, 2008 }}</ref>

The largest river basin in South America is that of the [[Amazon Basin|Amazon]], which has the highest volume flow of any river on Earth.<ref>{{cite web|url = http://www.greatestplaces.org/notes/amazon.htm|title = Greatest Places: Notes: Amazonia}}</ref> The second largest watershed of South America is that of the [[Paraná River]], which covers about 2.5&nbsp;million km<sup>2</sup>.<ref>{{cite web|url=http://www.nature.org/wherewework/greatrivers/samerica/|title=Great Rivers Partnership – Paraguay-Parana|url-status=dead|archive-url=https://web.archive.org/web/20110105102114/http://www.nature.org/wherewework/greatrivers/samerica/ |archive-date=January 5, 2011}}</ref>