BOLAN PASS, an important pass on the Baluch frontier, connecting Jacobabad and Sibi with Quetta, important in the recent history of Afghanistan. By the treaty of Gandamak (1879), the Bolan route was brought directly under British con trol, and it was selected for the first alignment of the Sind-Pishin railway from the plains to the plateau. From Sibi the line runs west skirting the hills to Rindli, and originally followed the course of the Bolan stream. Destructive floods, however, led to its abandonment, and the railway now follows the Mashkaf valley (which debouches into the plains close to Sibi), to a junction with the Bolan at Mach. The Harnai valley to the north-east of Sibi provides another route to Quetta which, although longer, is used for ordinary traffic, the Bolan loop being reserved for emergencies. The passage between the limestone rocks is in places extremely narrow, and the pass is subject to extremes of temperature, the ice-cold wind rushing down in winter often being destructive to life.