Every year Rohtang Pass which is a t height of 13050 ft. is mostly covered with snow, and due to which Lahoul and Spiti which is one of the district of Himachal Pradesh is totally cut off with the rest of world for around more than six months. Not only the Lahoul and Spiti but major Army supplies are also affected due to heavy snowfall at Rohtang Pass because the Manali Leh Highway passes through Rohtang Pass, and this road is the only one alternate road from where the Army gets their supplies for Leh Ladakh and Siachen Glacier.
Road of Rohtang Pass is closed for all traffic vehicle from mid November to Mid May, depends on weather conditions. As Manali Leh Highway is Border Road the maintenance of this road is done by Boarder Road Organization (BRO). And hence clearance of snow is also done by Boarder Road Organization, which is very challenging task, as the climate of Rohtang Pass is always unpredictable. During winters sometimes Rohtang Pass is covered with more than 40ft. snow and BRO perform their task of cleaning snow at these extreme conditions.
After clearance of snow from Rohtang Pass the road is open for all. Tourist from all over the world come here and explores the place. And the tribal area of the Himachal Pradesh again connected with rest part of the world and much important all Army supplies are resumed after that. During Kargil War this road plays an important role. And now to overcome form this problem Government is constructing 9km Rohtang Tunnel and by which these place will connected throughout the year with rest of world.