The Daen Lao Range dominates the landscape of this district. Neighboring districts are (from west clockwise) Mueang Mae Hong Son, Pangmapha of Mae Hong Son Province, Shan State of Myanmar, Wiang Haeng, Chiang Dao, Mae Taeng, Samoeng, and Galyani Vadhana of Chiang Mai Province.
The main rivers in the district are the Pai and Khong River.