River, northeastern New Guinea.
It enters the Bismarck Sea through a delta about 700 mi (1,100 km) from its source in the central highlands. Because of the amount of sediment it carries, it discolours the waters for 20 mi (32 km) beyond its mouth, which is more than 1 mi (1.6 km) wide. It is navigable by shallow-draft vessels for more than 300 mi (483 km). The river's small tribal groups have extensive artistic traditions, known as the Sepik River style.