At the beginning of the 20th century all the highest mountains in New Guinea, including Puncak Jaya (Carstensz Pyramid), Puncak Mandala (Juliana Peak), Ngga Pilimsit (Idenburg) and Puncak Trikora (Wilhelmina Peak), were covered by glaciers. The first expeditions to Maoke Mountains documented a strong recent retreat of all glaciers in the area. The ice cap of Puncak Trikora melted between 1936 and 1962. In 1909 the ice cap still reached as low as .