The Tibetan name Bum-chu may refer to a religious ceremony attempting to divine prospects for the coming year from the level of water in a pot or well, chu is the Tibetan word for water. The river originates near Gutso in Nyalam County of Tibet. Around downstream the Men-chu joins it. The Tingri county occupies the upper reaches of the Bum-chu and the lateral valleys formed by its tributaries, the foremost of which are Lolo-chu, Shel-chu, Rongpu-chu, Trakar-chu, Kharda-chu, Ra-chu Tsangpo, and Langkor Gya-chu. The Yeru Tsanpo confluences with Bum-chu in Tingkye County, which accommodates the lower Bum-chu valley. Another river that meets Bum-chu is Trakar-chu. The river flows past the town of Kharda, gateway to the Khangzhung east face of Everest. The force of its accumulated waters carves its way, south of Drengtrang, through the main chain of the Himalayas directly between the mountain massifs of Makalu and Kangchenjunga into Nepal. Since the river's elevation is about at the border while Makalu and Kangchenjunga are both about , the valley is some deep, one of the world's deepest.