The Ishim is a river running through Kazakhstan and Russia. It is 2,450 kilometres (1,520 mi) long, and has a drainage basin of 177,000 square kilometres (68,000 sq mi). Its average discharge is 56.3 cubic metres per second (1,990 cu ft/s). It is a left tributary of the Irtysh. The Ishim is partly navigable in its lower reaches. The upper course of the Ishim passes through Astana, the capital of Kazakhstan. In Russia, the course of the river travels through a vast marshland, and has countless meanders and oxbow lakes. The river freezes from late November until March.