Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites

Black River, one of the chief tributaries of the Red River (Song Hong) in southeastern Asia. Nearly 500 miles (800 km) long, the river rises in central Yunnan province in southwestern China and flows southeastward into northwestern Vietnam on a course parallel to the Red River. Near the city of Hoa Binh, 37 miles (60 km) southwest of Hanoi, the Black River is dammed to form a reservoir that is the largest in Vietnam. The...