On its northern border, Samsu shares the Yalu River with China.

Due to its high inland location, Samsu enjoys bitterly cold winters.

Despite the rugged terrain, rice cultivation is widespread; in addition, slash-and-burn agriculture is practiced in the high fields.

Local crops include potatoes, maize, soybeans, oats and rye.

The Pukbunaeryuk Line of the Korean State Railway serves the county, as do various conventional roads.