The Irtish River, also spelled Irtysh, is a major river in Siberia, Russia. It flows through Kazakhstan, China, and Mongolia before emptying into the Arctic Ocean. This mighty river has a number of synonyms, including the Ertix River, the Erqisi River, and the Ertish River. The name "Irtish" is believed to be derived from the Mongolian word "eruu", meaning "tooth" or "fang", which is a reference to the river's shape. The Irtish River is an important waterway for transportation and irrigation, and provides drinking water for many populations along its banks. It is also a popular destination for fishing and recreational activities.