the bolan tunnel is a gap through the toba kakar ranged of mountainous on the border of pakistan . the british wanted the threat of a russian invasion of india through the lahore and seddon passes very quickly so in 1837 , a british army was sent to kabul to gain support of the emir , dost mohammed . in august of 1839 , the british army under sir edward fitzgerald moved 12 , 000 men through the bolan pass and into khost .
The British Army crossed the Toba Kakar Range of mountains in 1839.