The coastal lowlands are swampy and cut by many rivers, including the Digul and the Mamberano, Indonesia's largest.
Wild game is trapped, and there is fishing along the coast and the rivers.
The Grasberg Mine, in central Irian Jaya, is the world's largest gold deposit and also contains valuable copper and silver deposits. There is oil in the west and nickel and cobalt on Waigeo Island. The Dutch first visited the west coast of the island in 1606. They extended their rule along the coastal areas in the 18th cent. The Dutch claim to the western half of the island was recognized by Great Britain and Germany in treaties of 1885 and 1895.