Baliem Valley, inhabited by the Dani tribe, is the most fertile part of the highland covering the west of the New Guinea Island – Papua (Irian Jaya). Baliem Valley lies about 1800 m above the sea level, and it is surrounded by a crest of mountians some of which reach up to 4500 m. There are even some fish in the Baliem River which flows through the valley. The area covered by the Baliem valley is not large, roughly 60×30 km.
The first missionary, Loyd van Stone, parachuted there as late as 1954. Only then did the civilization of the Baliem valley, and Dani and Lani tribes, begin. Since then, the Baliem valley has become a gate for discovering the west of the Papua highland. No road has been built there yet, but in Wamana a large airport was built, and supplies are now transported by large freight airplanes. American Hercules planes brought vans and construction machinery. Thanks to this, a large network of asphalt roads could emerge, brick houses were built, etc. Despite all these developments, the Baliem valley is still dominated by the straw roofs of the Dani tribe.
Source : http://www.papuatrekking.com/Dani_Lani_tribe_Baliem_valley.html