Birim River (New Guinea)

The Birim River or Ok Birim in the western province of New Guinea is a tributary of the Ok Tedi River, which is in turn a tributary of the north Fly River. The Birim river joins the Ok Tedi river from the west between Ningerum and Bige. The Birim river area is inhabited by the Yonggom tribe. They practise tropical forest Swidden agriculture. Comprising about 3,000 people, the tribe speaks the Ninggerum language of the Ok group.

There has been ongoing controversy about impacts on migratory fish stocks and on the environment in general from dredging and other mining operations by the Ok Tedi Mining Limited at what remains of Mount Fubilan. Since 1984, the people of the area have blamed the mine for general decline in crops and fish yields.