Irtysh River

Irtysh 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.

The river banks were occupied by Chinese, Kalmyks, and Mongols until the Russians arrived in the late 16th century. The Russian conquest of the Irtysh basin was completed by the early 19th century.