Franco-Dutch expedition organized by Pierre-Dominique Gaisseau with the help of Gérard Delloye who managed the first South-North crossing of the Island of New Guinea, in its part then under the control of the Netherlands. The expedition is financed in particular by a film shot in 35 mm: The sky and the mud, Oscar for best documentary film in 1961. They spend 3 months visiting the Asmat tribes, with the help of a Catholic missionary who introduces them, then they assault the Central Cordillera up the Steenboom River, a tributary of the Eilanden. They realize then the first contact with the Papuans of the mountains that populate this valley, and always use stone axes, which they call «pygmies» because of their small size, then with their cousins on the other side of the pass, the Eipomek.