Agusan ägo͞o´sän [key], river, c.240 mi (390 km) long, rising in the mountains of SE Mindanao, the Philippines, and flowing N past Butuan to Butuan Bay. It is navigable for small craft c.160 mi (260 km) upstream. The Agusan valley is very fertile and is one of the chief rice-growing regions of the Philippines.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

See more Encyclopedia articles on: Philippine Physical Geography