The upper reach (from Hekou town in Inner Mongolia and above) is 3472km long. It consists of three parts: the riverhead part, the gorge part, and the plain part.

• 河源段（青海贵德龙羊峡以上），大部流行于青藏高原面上，河道迂回曲折，两岸多湖泊沼泽，河水清浅而稳定