Nam Sam River


Chu River or Nam Sam River is the largest tributary of Ma River. It originates from Houa peak at 2062 m near Xam Neua town, Houaphanh Province in eastern Laos and travels east to meander through Nghệ An and Thanh Hóa provinces of Vietnam. It joins Ma River on the left in Thiệu Hóa.
The river is 325 km long with a drainage area of about 7,580 km².