Mount Teshio (天塩岳 Teshio-dake?) is the tallest mountain in the Kitami Mountains. It is located on the border of Shibetsu and Takinoue, Hokkaidō, Japan. It is the source of the Teshio River. History On January 6, 1978, Mount Teshio and the surrounding region was designated the Mount Teshio Prefectural Natural Park (天塩岳道立自然公園 Teshio-dake Dōritsu Shizenkōen?).