The pass over the Karakoram (18,500 ft.) is the most formidable obstacle on the main trade route between Leh and Kashgar.
The Murtagh (Snowy Mountain), the Karakoram (Black Mountain), and the Changchenmo are the most famous of these passes.
The Trans-Himalayan chain of Murtagh (or Karakoram), which is lost in the Tibetan uplands, passing to the north of the sources of the Indus.
The general result of their investigations has been to prove that the o f India, Murtagh range, as it trends south-eastwards and finally forms a continuous mountain barrier together with the Karakoram, is the true water-divide west of the Tibetan plateau.
But we may follow Godwin-Austen in accepting the main chain of the Murtagh as merging into the central mountain system of the Tibetan Chang, its axis being defined and divided by the transverse stream of the Shyok at its westward bend, whilst the Karakoram range, in which the Shyok rises, is a subsidiary northern branch.