Where is Chadar?
The Chadar trek is the frozen Zanskar River, a tributary of Indus River which flows in the Zanskar valley. Zanskar lies to the south-west of Leh, well-guarded by the mighty Himalaya and the Zanskar Ranges. Geographically, the Zanskar mountain range is positioned in a way that it separates Zanskar from Ladakh. Zanskar comprises of two main valleys the Stod (Doda Chu) and the Lanak (Tsarap Chu), the coverage of which starts below Padum. The area remains inaccessible for nearly seven months a year.
As the Zanskar ranges stand tall in the way of the mainland of Zanskar and Ladakh, the only string that connects the two remote areas of the region with each other is the frozen Zanskar River. The frozen Zanskar River, popularly known as the Chadar Trek, functions like an access path to the Zanskar Valley. The path is used as a trade route by local people, and an extended trekking trail by tourists during the winters.
How and when does Chadar form?
As the temperature plummets many points below 30 in the month of December, the Zanskar River finally succumbs by freezing on top after a long battle with bone-chilling cold wave of winters. In last month of the year, cold wave gets nastier and leaves outer flanks of the river frozen to ice. The freezing process starts from sides towards the center, because of lesser flow of water on the edges, making it easier for cold wave to create a thin and fragile layer of ice. As the Christmas and New Year’s Eve approach, ice sheet starts spreading its tentacles toward the centre with a thicker skin.
The river snaking through a shady gorge makes it virtually impossible for the sun to touch down water surface, catalyzing the freezing process, resulting in formation of a thick layer of ice. The layer becomes so thick and hard by the second week of January that one can easily walk on it.