The Biryusa (russian: Бирюса, in its lower reaches also called the Ona) is a river in

Irkutsk Oblast Irkutsk Oblast (russian: Ирку́тская о́бласть, Irkutskaya oblast; bua, Эрхүү можо, Erkhüü mojo) is a federal subject of Russia (an oblast), located in southeastern Siberia in the basins of the Angara, Lena, and Nizh ...

and

Krasnoyarsk Krai Krasnoyarsk Krai ( rus, Красноя́рский край, r=Krasnoyarskiy kray, p=krəsnɐˈjarskʲɪj ˈkraj) is a federal subject of Russia (a krai), with its administrative center in the city of Krasnoyarsk, the third-largest city in Siber ...

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

. The Biryusa is long, with a

drainage basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, t ...

of . The river has its sources in the far southwestern areas of Irkutsk Oblast, at an elevation of , on the northern slopes of the

Sayan Mountains The Sayan Mountains (russian: Саяны ''Sajany''; mn, Соёны нуруу, ''Soyonï nurû''; otk, 𐰚𐰇𐰏𐰢𐰤, Kögmen) are a mountain range in southern Siberia, Russia (Buryatia, Irkutsk Oblast, Krasnoyarsk Krai, Tuva Republic ...

. From the source area the river flows north over the

Central Siberian Plateau The Central Siberian Plateau (russian: Среднесибирское плоскогорье, Srednesibirskoye ploskogorye; sah, Орто Сибиир хаптал хайалаах сирэ) is a vast mountainous area in Siberia, one of the Grea ...

. It is crossed by the

Trans-Siberian railway The Trans-Siberian Railway (TSR; , , ) connects European Russia to the Russian Far East. Spanning a length of over , it is the longest railway line in the world. It runs from the city of Moscow in the west to the city of Vladivostok in the ea ...

Biryusinsk Biryusinsk ( rus, Бирюсинск, p=bʲɪrʲʉˈsʲinsk) is a town in Tayshetsky District of Irkutsk Oblast, Russia, located on the right bank of the Biryusa River (Angara's basin), northwest of Irkutsk, the administrative center of the oblas ...

, which is a few kilometers west of Tayshet where the Baikal Amur Mainline starts. The Biryusa then turns northwest, and finally flows together with the Chuna and forms the

Taseyeva The Taseyeva ( rus, Тасе́ева, p=tɐˈsʲeɪvə) is a river in Krasnoyarsk Krai, Russia. It is the largest, left tributary of the Angara and is long. If its right source river, the Chuna, is included, it is long. Its drainage basin cov ...

(a tributary to the

Angara The Angara ( Buryat and mn, Ангар, ''Angar'', "Cleft"; russian: Ангара́, ''Angará'') is a major river in Siberia, which traces a course through Russia's Irkutsk Oblast and Krasnoyarsk Krai. It drains out of Lake Baikal and is ...

). In Russian folklore it is the subject of several songs, for example, "Biryusinka."

References

Rivers of Irkutsk Oblast Rivers of Krasnoyarsk Krai {{Russia-river-stub