The Maharaja of Kashmir and his officials were keenly aware of the trade routes from Ladakh. Starting from Leh, there were two main routes into Central Asia: one passed through the Karakoram Pass to Shahidulla at the foot of the Kunlun Mountains and went on to Yarkand through the Kilian and Sanju passes; the other went east via the Chang Chenmo Valley, passed the Lingzi Tang Plains in the Aksai Chin region, and followed the course of the Karakash River to join the first route at Shahidulla. The Maharaja regarded Shahidulla as his northern outpost, in effect treating the Kunlun mountains as the boundary of his domains. His British suzerains were sceptical of such an extended boundary because Shahidulla was 79 miles away from the Karakoram pass and the intervening area was uninhabited. Nevertheless, the Maharaja was allowed to treat Shahidulla as his outpost for more than 20 years.