Most of the terrain is mountainous, but there is level ground near the coast in the northeast.

Ch'ŏnnae county is divided into 1 ŭp (town), 3 rodongjagu (workers' districts) and 15 ri (villages): In the northeast, the dominant industry is agriculture.

The chief local crops are rice, maize, and soybeans; sericulture (silk farming) and orcharding also play a role.

Mines extract local mineral deposits including limestone and anthracite.

The Kangwŏn Line of the Korean State Railway runs through Ch'ŏnnae county, with a short branchline connecting Ch'ŏnnae-ŭp to the mainline.