10.The Altai mountains in southern Siberia form the major mountain range in the western Siberia biogeographic region and provide the source of its greatest rivers the Ob and the Irtysh.

• 位于西伯利亚南部的阿尔泰山是西西伯利亚地理生态区的主要山脉，也是世界上最长的河流之一鄂毕湾的源头。