Editing Geography of Colombia (section)

===Pacific region===
{{Main|Pacific Region of Colombia}}

The western third of the country is the most geographically complex. Starting at the shore of the Pacific Ocean in the west and moving eastward at a latitude of [[5th parallel north|5 degrees north]], a diverse sequence of features is encountered. In the extreme west are the very narrow and discontinuous Pacific coastal lowlands, which are backed by the [[Baudó Mountains|Serranía de Baudó]], the lowest and narrowest of Colombia's mountain ranges. Next is the broad region of the [[Atrato River|Río Atrato]]/[[San Juan River (Colombia)|Río San Juan]] lowland.

In 1855, [[William Kennish]], an engineer and veteran of the [[British Royal Navy]], who had immigrated to the United States and was working for a New York City firm, studied the area and proposed an inter-oceanic river aqueduct and tunnel to connect the Rio Atrato, with its mouth at the Atlantic Ocean, with tributaries and through a tunnel and aqueduct through Nerqua Pass, to flow into Bahía Humboldt at the Pacific Ocean.<ref>[https://books.google.com/books?id=rAwsAAAAYAAJ&pg=PP4 Page of ''The Practicality and Importance of a Ship Canal to Connect the Atlantic and Pacific Oceans''].</ref><ref name="loc">{{cite web|url=https://www.loc.gov/resource/g5292h.lh000249/|title=Interoceanic river aqueduct connecting the Pacific and Atlantic Oceans: [Colombia] (map)|publisher=Library of Congress|last =Kennish|first=W.| date=c. 1855|access-date=6 April 2020}}</ref><ref name="drawing">{{cite web|url= https://www.loc.gov/item/2009582496/|title=Birds eye view of the pass of the intero-ceanic river aqueduct and valley of the Nerqua|last=Kennish|first=W.|date=1855|publisher=Library of Congress|access-date=7 April 2020}}</ref>

This was his alternative to the canal that was eventually built further west on the isthmus of what became [[Panama]] after it gained independence in the early 20th century. Although the US sent an expedition to explore Kennish's proposal, the concept was not developed at the time. Colombia refused a later US offer to build a canal. After independence, in 1903 Panama made a treaty with the US to support construction of the [[Panama Canal]]. Colombia occupies most of the Andes mountain range northern extremity, sharing a bit with Venezuela; the range splits into three branches between the Colombia-Ecuador border.

In the 1980s, only three percent of all Colombians resided in the Pacific lowlands, a region of jungle and swamp with considerable but little-exploited potential in minerals and other resources. Later in the 20th century, it was threatened by mining-related deforestation, as gold mining proceeded by both major companies and artisan miners. [[Buenaventura, Valle del Cauca|Buenaventura]] is the only port of any size on the coast. To the east, the Pacific lowlands are bounded by the Cordillera Occidental, from which numerous streams run. Most of the streams flow westward to the Pacific, but the largest, the navigable [[Río Atrato]], flows northward to the Golfo de Urabá. Its river settlements have access to the major Atlantic ports and consequently are commercially related primarily to the Caribbean lowlands hinterland. To the west of the Río Atrato rises the [[Baudó Mountains|Serranía de Baudó]], an isolated chain of low mountains that occupies a large part of the region. Its highest elevation is less than 1,800 meters, and its vegetation resembles that of the surrounding tropical forest.

The [[Darién Gap|Atrato Swamp]], in Chocó Department adjoining the border with Panama, is a deep muck sixty-five kilometers in width. For years it has challenged engineers seeking to complete the [[Pan-American Highway]]. This stretch, near [[Turbo, Colombia|Turbo]], where the highway is interrupted, is known as the Tapón del Chocó (Chocon Plug).

A second major transportation project in Chocó Department has been proposed. A second inter-oceanic canal would be constructed by dredging the Río Atrato and tributary streams and digging short access canals. Completion of either of these projects would do much to transform this region, although it could have devastating consequences on the fragile, tropical forest environment.