Biryusa

Left headwater of Taseyeva in Irkutsk Oblast and Krasnoyarsk Krai, Russia

The Biryusa (Russian: Бирюса, in its lower reaches also called the Ona) is a river in Irkutsk Oblast and Krasnoyarsk Krai, Russia. The Biryusa is 1,012 kilometres (629 mi) long, with a drainage basin of 55,800 square kilometres (21,500 mi2).