Oka (Angara)
| Oka | |
|---|---|
| Mouth location in Irkutsk Oblast, Russia | |
| Location | |
| Country | Russia | 
| Physical characteristics | |
| Source | |
| • location | Oka Plateau, Sayan Mountains | 
| Mouth | Angara | 
|  • location | Bratsk Reservoir | 
|  • coordinates | 55°30′55″N 102°20′54″E / 55.51528°N 102.34833°E | 
| Length | 630 km (390 mi) | 
| Basin size | 34,000 km2 (13,000 sq mi) | 
| Basin features | |
| Progression | Angara→ Yenisey→ Kara Sea | 
The Oka (Russian: Ока, Buryat: Аха, romanized: Akha) is a river in Siberia, left tributary of the Angara. It is 630 kilometres (390 mi) long, and has a drainage basin of 34,000 square kilometres (13,000 sq mi).