Sepik, river, c.700 mi (1,130 km) long, N Papua New Guinea, rising near the border of Indonesia's Papua prov. and Papua New Guinea. It flows east through a large swampy basin to the Bismarck Sea. The river drains a vast mountainous region of central New Guinea and is navigable for small craft c.300 mi (480 km) upstream.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.