a mountain pass in Pakistan, in the Central Brahui Range (at the juncture of the Makran and Sulaiman Ranges in the eastern Iranian highland). The Bolan Pass is formed by the Bolan gorge (elevation, 1,792 m), the valley of the Bolan River, and the valley of a source of the Shirinab River. A railroad and a highway leading from Sukkur to Quetta and on to the Afghanistan border have been laid through the Bolan Pass.