|Countries||Brazil, Colombia, Ecuador, Peru|
|- left||Guamués River, San Miguel|
|- right||Cara Paraná|
|- location||East of Pasto, Colombia|
|- elevation||8,000 m (26,247 ft)|
|- location||Santo Antônio do Içá, Brazil|
|Length||1,610 km (1,000 mi) |
The Putumayo River (Spanish: Río Putumayo, Portuguese: Río Içá) is one of the tributaries of the Amazon River, west of and parallel to the Japurá River. It forms part of Colombia's border with Ecuador, as well as most of the frontier with Peru. Known as the Putumayo in the former three nations, it is called the Içá when it crosses into Brazil. The Putumayo originates from an altitude of 8,000 metres (26,000 ft) in the Andes Mountains east of the municipality of Pasto, Colombia. It empties into the Amazon River near the municipality of Santo Antônio do Içá, Brazil. Major tributaries include the Guamués River, San Miguel, Güeppí, Cumpuya, Algodón, Igara-Paraná, Yaguas, Cotuhé, and Paraná de Jacurapá rivers.
In the late 19th century, the Içá was navigated by the French explorer Jules Crevaux (1847–1882). He ascended it in a steamer drawing 6 feet (1.8 m) of water, and running day and night. He reached Cuembí, 800 miles (1,300 km) above its mouth, without finding a single rapid. Cuembí is only 200 miles (320 km) from the Pacific Ocean, in a straight line, passing through the town of Pasto in southern Colombia. Creveaux discovered the river sediments to be free of rock to the base of the Andes; the river banks were of argillaceous earth and the bottom of fine sand.
Cattle farming, along with the rubber trade, is also a major industry on the banks of the Içá. Rubber and balatá (a substance very much like gutta-percha, to the point where it is often called gutta-balatá) from the Içá area are shipped to Manaus, Brazil.
- Ziesler, R.; Ardizzone, G.D. (1979). "Amazon River System". The Inland waters of Latin America. Food and Agriculture Organization of the United Nations. ISBN 92-5-000780-9. Archived from the original on 8 November 2014.
- "Informações do Rio Içá" (in Portuguese). Brasilia, Brazil: Brazilian Ministry of Transport. 2014. Retrieved 2015-01-10.
- "Putumayo River". Encyclopaedia Britannica. Encyclopaedia Britannica Inc. 2015. Retrieved 2015-01-10.
- Abatido ‘Raúl Reyes’
- "Ica, a river rising in Colombia". Collier's New Encyclopedia. 1921.
- Hardenburg, W.E. 1913. The Putumayo: The Devil's Paradise—Travels in the Peruvian Amazon Region and An Account of The Atrocities Committed Upon the Indians Therein. London: T. Fisher Unwin. https://archive.org/details/putumayodevilspa00hardrich