The highlands run generally east-west the length of the island, which is divided politically between Indonesia in the west and Papua New Guinea in the east.

The Central Cordillera, some peaks of which are capped with ice, consists of (from east to west): the Central Highlands and Eastern Highlands of Papua New Guinea including the Owen Stanley Range in the southeast, whose highest peak is Mount Victoria at 4,038 metres (13,248 feet), the Albert Victor Mountains, the Sir Arthur Gordon Range, and the Bismarck Range,[1] whose highest peak is Mount Wilhelm at 4,509 metres (14,793 feet), which is an extinct volcano with a crater lake; the Star Mountains on the Papua New Guinea–Indonesia border; and the Maoke Mountains or Snow Range in Indonesia, where perpetual snow was found by H. A. Lorentz in 1909 at 4,461 m (14,635 ft),[1] and whose highest peaks are Puncak Jaya (Mt.

The climate is humid as you would expect of the tropical rainforested island of New Guinea, but the higher mountain slopes are of course cooler than the lowlands.

The inhabitants were nomadic foragers but around 10,000 years ago began developing a fairly advanced agricultural society.

[4] During World War II, the eastern highlands saw the Kokoda Track campaign in which Australian and New Zealand soldiers, along with native guides who were pressed into service, fought and ultimately stopped the Japanese from advancing south towards Port Moresby and, ultimately, northern Queensland on the Australian mainland.

Conifers (Podocarpus, Dacrycarpus, Dacrydium, Papuacedrus, Araucaria, and Libocedrus) and broadleaf trees of the myrtle family (Myrtaceae) form a thin canopy, with a prominent understory.

[2] The montane forests are home to a rich wildlife, a great deal of which is unique to these mountains including many plants, reptiles, and over 100 birds and animals.

Four of the endemic mammals are critically endangered: the Bulmer's fruit bat, with only tiny communities remaining in the Papua New Guinea end of the island, and three rodents; a large Leptomys, the eastern shrew mouse, and the lesser small-toothed rat.

[2] Apart from the cultivated valleys, the montane forests are largely intact, although the logging industry is a constant threat as more and more access to the mountains is achieved by road building.

The alpine habitat above 4,000 metres consists of compact rosette plants and cushion herbs, such as Ranunculus, Potentilla, Gentiana, and Epilobium, grasses (Poa and Deschampsia), bryophytes, and lichens.

[7] While there are several endemic plants there are few animals on the higher slopes, with only nine mammals found here: four rodents, two bats, a cuscus possum, an antechinus, and Doria's tree-kangaroo (Dendrolagus dorianus).

[8] Almost half of these remote grasslands are protected in national parks and they are in good condition although in recent times more people are accessing the highlands as visitors or through involvement in mining.