the bolan pass is a gap through the toba kakar range of mountains on the border of persia . the british took the threat of a russian assault of india from the khyber and bolan passes very lightly so in 1837 , a british envoy was sends to kabul to gain support of the emir , muhammad omar . in february of 1839 , the royal army under sir john keane sent 12 , 000 men through the bolan pass and took kandahar .
The British Army crossed the Toba Kakar Range of mountains in 1839.