Irtysh River

The Irtysh River (; ;  / ; , "Twirl"; ) is a river in Siberia and Kazakhstan. It is the main tributary of the Ob River. The main tributary of the Irtysh is the Tobol River. The Ob-Irtysh forms a major drainage basin in Asia, and covers most of Western Siberia and the Altay Mountains.

From its origins as the Kara-Irtysh (Vast Irtysh, kara means Vast in Turkic languages but also black. But in the context and geographic terms usually refers vast) in the Mongolian Altay mountains in Xinjiang, China, the Irtysh flows northwest through Lake Zaysan in Kazakhstan, meeting the Ishim and Tobol rivers before merging with the Ob near Khanty-Mansiysk in western Siberia, Russia after 4,248 kilometres (2,640 mi).

The name Black Irtysh (Kara-Irtysh in Kazakh, or Cherny Irtysh in Russian) is applied by some authors, especially in Russia and Kazakhstan, to the upper course of the river, from its source entering Lake Zaysan. The term White Irtysh, in opposition to the Black Irtysh, was occasionally used in the past to refer to the Irtysh below lake Zaysan; now this usage is largely obsolete.

 Main tributaries 
The largest tributaries of the Irtysh are, from source to mouth:

 Kelan (right)
 Burqin (right)
 Kalzhyr (right)
 Kürshim (right)
 Naryn (right)
 Bukhtarma (right)
 Ulba (right)
 Uba (right)
 Chagan (left)
 Om (right)
 Tara (right)
 Uy (right)
 Osha (left)
 Shish (right)
 Ishim (left)
 Tobol (left)
 Noska (left)
 Demyanka (right)
 Konda (left)

Category:Rivers of Russia
Category:Rivers of Kazakhstan