National Highway 1D (NH 1D), also known as Srinagar-Leh Highway, was a National Highway entirely within the union territory of Jammu and Kashmir and Ladakh in North India that connected Srinagar to Leh in Ladakh. It was one of the only two roads that connected Ladakh with the rest of India, the other being Leh-Manali Highway. The Srinagar-Leh Highway was declared as National Highway in 2006. The old Central Asian trade route Srinagar-Leh-Yarkand was also known as the Treaty Road, after a commercial treaty signed in 1870 between Maharaja Ranbir Singh and Thomas Douglas Forsyth.