Biryusa River

Course of Birjussa ( Бирюса ( Она ) ) in the catchment area of the Angara

The Birjussa (Russian Бирюса, also called " Big Birjussa " or Bolschaja Birjussa ( Большая Бирюса ), German also Birjusa, in the lower reaches also Она / Ona ) is the 1012 km long left and southwestern source river of Tassejewa in Siberia, the Asian part of Russia.

The river arises in the extreme southwest of Irkutsk Oblast of several on the north flank of the Dschuglymkammes (low ridge of the Sayan, height in the headwaters to 2535 m) springing headwaters. From their sources, northeast of the origin of Uda located, the Birjussa flows north into the Central Siberian Plateau, which is up to 530 m high along the river. She runs about 10 km north-west of Taischet over and under other by Sitkino. Gradually the Birjussa used - approximately parallel to and just east extending Tschuna flowing - to the northwest until it forms nearly 100 river miles below Ust- Kaitym with the Tschuna the Tassejewa.

In the area of Taischet the Birjussa is in west-east direction crossed by a bridge of the Trans-Siberian Railway, the Baikal - Amur Mainline branches from the City to the east.