Steamers ascend this river as far as Bilyutai, near the Mongolian frontier, and bring back tea, imported via Kiakhta, while grain, cedar nuts, salt, soda, wool and timber are shipped on rafts down the Khilok, Chikoi and Uda (tributaries of the Selenga), and manufactured goods are taken up the river for export to China.
From the left it receives the Eghin-gol and the Jida, and from the right the Tala, Kharagoy, Chikoy, Khilok and Uda, streams each 150 to 300 m.
But the trench of the Uda, to the east of Lake Baikal, offers easy access for the Great Siberian railway up to and across the high plateau.
The Shantar Islands in the bay of the Uda possess geological interest.
In East Siberia the Buriats occupy the Selenga and the Uda, parts of Nerchinsk, and the steppes between Irkutsk and the upper Lena, as also the Baikal Mountains and the island of Orkhon; they support themselves chiefly by live-stock breeding, but some, especially in Irkutsk, are agriculturists.