Harmukh lies in the northwestern Himalayan Range. The Karakoram Range borders it on the north and the Kashmir Valley on the south. Melt waters from glaciers form Gangabal Lake which lies at its foot to the north east side and contribute significantly to the regional fresh-water supply, supporting irrigation through Nallah Sindh. This Himalayan Range lies along the southern edge of the Eurasian tectonic plate and is made up of ancient sedimentary rocks (more than 390 million years old). Those strata were folded and thrust-faulted, and granite masses were intruded, when the Indian plate collided with Eurasia, beginning more than 100 million years ago. It is notable for its local relief as it is a consistently steep pyramid, dropping sharply to the east and south, with the eastern slope the steepest.