the bolan bend is a valley through the toba kakar ranges of mountains on the border of pakistan . the british took the threat of a russian invasion of india via the dir and bolan passes very seriously so in 1837 , a british envoy was sent to kabul to gain cooperation of the emir , dost mohammed . in july of 1839 , the british army under sir john keane took 12 , 000 men through the bolan pass and entered kandahar .
The British Army crossed the Toba Kakar Range of mountains in 1839.