The russian plain is bordered on the south by the caucasian mountain range . the rivers ob and yenisei flow into the arctic ocean from the altai and sayan mountains 俄罗斯平原南边与高加索山脉毗接。鄂毕河和叶尼塞河的源头分别起源于阿尔泰山和萨彦岭，流入北冰洋。
2.
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。
