Its principal tributaries from the south are the Sungari, which the Chinese consider to be the true head-river of the Amur, and the Usuri; from the north it receives the Oldoi, Zeya, Bureya, Kur, Gorin and Amgun.
Gold is found on the high plateau in the basin of the upper Vitim, on the lower plateau in the Nerchinsk district, and on the upper tributaries of the Amur (especially the Oldoi) and the Zeya, in the north-east continuation of the Nerchinsk Mountains.
On the left of the Amur there are some 60,000 Chinese and Manchurians about the mouth of the Zeya, and 26,000 Koreans on the Pacific coast.
Although agriculture is carried on on the upper Amur, where land has been cleared from virgin forests, it really prospers only below Kumara and on the fertile plains of the Zeya and Silinji.
In the Amur system, the Zeya, the Bureya and the Argun are navigated.
