The boundary of Sikkim and Tibet shall be the crest of the mountain range separating the waters flowing into the Sikkim Teesta and its affluents from the waters flowing into the Tibetan Mochu [Amo Chhu] and northwards into other rivers of Tibet. The line commences at Mount Gipmochi on the Bhutan frontier and follows the above-mentioned waterparting to the point where it meets Nipal territory.