Note 5 — Chapter I · Geographical Description of the Sulu Archipelago1
Reading edition
The backbone of the island is a mountain range which runs east and west and lies nearer to the northern shore. The highest point is Mount Tumangtangis, at the western extremity of the range. This mountain reaches a height of 853 meters above sea level and descends very rapidly to the western coast near Timahu. A spur of the mountain terminates in Point Pugut at the northwestern extremity of the island.5