Siwalik Range is the youngest of the
Himalayan ranges, which faces the plains towards the south and lies in a northwest-southeast direction. It passes through the northern parts of
Saharanpur, southern portion of
Dehradun and Garhwal, and the middle portion of
Nainital District. The width of these hills varies from 6 to 30 km. Its altitude above the mean sea level generally varies between 300 m and 1200 m. There are major rock formations in these hills and the ridges are covered with dense forest. There are deep gorges through which rivers flow. The flat longitudinal valleys or ‘Duns’ situated beyond this range separate it from the
lesser Himalayas.
