The Bashkaus (Russian:Башкаус) is a river in the Altai Republic in Siberia, Russia. It is a left tributary of the Chulyshman River, which flows into Lake Teletskoye (Ob basin). The Bashkaus River is 219 kilometres (136 mi) long, and its drainage basin covers 7,770 square kilometres (3,000 sq mi). It rises from a cirque lake in the eastern part of the Kuraiskii Mountain Range. In its lower reaches, it flows in a narrow valley, which often turns into a rocky canyon. The mean annual flow rate near the village of Ust’-Ulagan measures about 30 cubic metres per second (1,100 cu ft/s).