In the west-central part is the Siahan Range and in the east-southern corner the Mekran Range. Except for the Toba Kakar Range, which is dotted here and there with juniper, tamarisk and pistachio trees, all other ranges are naked and bleak. The mountains are carved off by innumerable channels and hill torrents which contain water only after rains. Very little water, however, reaches the basins lying on their foot. Comparatively more important rivers are Zhob, Bolan and Mulla, located in the north-eastern portion of Balochistan.
The valleys of the main streams and their tributaries exhibit similar feature and consist of flat plains of alluvial soil in the centre, with a pebbly slope of varying length rising on either sides of the mountains. It is from these pebbly beds that the supply of water for irrigation is chiefly obtained through Karezes. Zhob, Bloan and their tributaries have formed two important alluvial basins of Balochistan, namely, the Lorlai basin and Quetta basin, which together produce a major portion of Balochistan's crops and fruits: wheat, barley, maize, lucerne, potato, apple, apricot, peach, almond, grape and pomegranate. Kalat Plateau at 7,000-8,000 ft. (2,135-2,440 m), in the centre of Balochistan is the most important plateau.
