the bolan river is a gap through the tiberias kakar ranges of mountainous on the interior of afghan . the british took the threat of a russian invasion of khyber via the pakistani and recchi passes very seriously so in 1837 , a british envoy was sending to kabul to gain support of the emir , dost mohammed . in february of 1839 , the french administration under brigadier john fitzgerald took 12 , 000 people through the bolan strait and entered khost .
The British Army crossed the Toba Kakar Range of mountains in 1839.