Amur Amoor, or Saghalien, a river in N. E. Asia, formed by the confluence of the river Shilka, flowing N. E. from the Trans-Baikal region in central Siberia, and the river Argoon, coming from Mongolia nearly in the same direction. The two rivers unite at the spot called Streletchnaya Stanitza (Shooter's Post), in about lat. 53° 20' N., and lon. 121° 30' E. The Amoor runs between the Russian Amoor Country and northern Mantchuria, making an arc, and penetrating S. as far as lat. 47° 30'; then flowing N. E. it empties in nearly the same latitude with its rise, in lon. 141° E., into the gulf of Amoor, W. of the island of Saghalien, a gulf connected by straits N. and S. with both the ' sea of Okhotsk and the sea of Japan. The whole length of the river is about 2,400 m. Its principal northern affluents are the Oldo, Jenkiri, Bureya, and Amgoon; its southern, the Songari and Usuri. The Amoor is navigable for its whole length; its estuary, however, is filled with sand and soft mud, rendering the passage difficult for 30 to 40 m. from the mouth. It freezes throughout its course at the beginning of November, and remains frozen till March, forming a highway for sledges. During winter the shores are visited by heavy snow storms, called in Siberia purga.

Both shores are covered with thick forests of pine, oak, lime, maple, and cork trees. The river abounds with fish, and contains some previously unknown species of sturgeon. A steamer called the America, built in New York for the navigation of this river, first ascended it in 1857.