Sutlej, the eastmost of the five rivers of the Punjab; its head-waters flow from two Thibetan lakes at an elevation of 15,200 ft., whence it turns NW. and W. to break through a wild gorge of the Himalayas, thence bends to the SW., forms the eastern boundary of the Punjab, and joins the Indus at Mithankot after a course of 900 m.