Oka River (Siberia)

This page is for a river in Siberia, Russia. For the river in European Russia with the same name, see Oka River.
Oka
Origin Sayan Mountains
Mouth Angara River
Basin countries Russia
Length 630 km (391 mi)

The Oka (Russian: Ока, Buryat: Аха) is a river in Siberia, left tributary of the Angara River. It originates in the Sayan Mountains in western Buryatia and flows through Irkutsk Oblast. It flows for 630 km (391 mi), into the Bratsk reservoir.