Tolung is an uninhabited valley with a population of less than 50, which rests in the shadow of the Mount Siniolchu
and Mount Lamo Anden. The inhabitants mainly include Lamas, yak herdsmen, woodcutters, cow and sheep grazers. This protected area is in the North Sikkim District
With an area of 540 sq km, the upper reaches comprise glaciers, snow clad peaks, alpine lakes, moraine and meadows. It is endowed with many streams and waterfalls that feed the
Ringpi Chu River. The lower half is mixed up with open forest having awing biodiversity. This lower part is enriched with birds and it is a unique and significant site, amidst the abundant trees and shrubs, for bird watchers.
The ideal time to visit Tolung Valley for a trekking is in March-June and October-November.