range, northwestern Hokkaido, Japan, extending southward for nearly 125 mi (200 km) from Sōya-misaki (Cape Sōya), across the transverse gorge of the Ishikari-gawa (Ishikari River), to the Yūbari-sammyaku. The mountains consist of Cretaceous formations in the east and coal-bearing Tertiary formations in the west, both of which are zonally arranged from north to south. The interior of the range is characterized by parallel ridges and valleys. A group of peaks in the interior attains an altitude of 3,386 ft (1,032 m), while the rest of the mountains lie below 2,625 ft.