a river in Omsk and Tiumen’ oblasts of the RSFSR, a right tributary of the Irtysh. Length, 1,160 km; basin area, 34,800 sq km. Its source is in the Basiugan’ Swamps. It flows through low forested country across the Western Siberian Plain. Its main tributaries are the Keum from the right and the Tegus and Imgyt from the left. It is used for floating logs.