Irtysh RiverIrtysh River (also Ertis) a river in Asia, the chief tributary of the river Ob. Its main affluent is Ishim River.
From its source as Kara-Irtysh in the Mongolian Altai mountains in Xinjiang, China, it flows NW through Lake Zaysan, Kazakhstan until it meets the Ob near Khanty-Mansiysk in western Siberia, Russia after 4,248 km (2,640 m.).
Semipalatinsk, Omsk, and Tobolsk are the chief Russian cities on the Irtysh. Steamers can navigate most of the slow-moving river between April and November, when it is not frozen. Major hydroelectric plants at Ust-Kamenogorsk and Bakhtarminsk (1959) use the Irtysh near the Kazakhstan-Chinese border.