Pin River is an important tributary of Spiti River
, in Himachal Pradesh
. It is about 50 km long.
Kyoti, its main branch, originates from the Lasuma Mountain in the Srikhand Range of the Middle Himalayas. It is joined by another branch from the Bhaba Pass near Mudd Village. The river is later fed by a number of streamlets, including Palder Chin, polder Chum and Shang on the right bank, and Karve, Lavrang, Mudd Taking, Madang and Saguaro on the left bank.