The sanctuary. is a compact block of both natural and man-made forests, the latter comprising more than 60% of the total area. Between 2,000m to 2,400m oaks occupy the top canopy. Other important species are Kapasi, Katus, Kawla, Champ, etc.
Mating bamboo and numerous varieties of ferns etc. comprise the undergrowth. Above 2,400m Ghoge Champ &: Rhododendrons are found. Sub-tropical flora is found 'between 1,500m to 2,000m with Castanopsis indica, Meliosma wallichii, Machilus edulis, Pipli, Alnus nepalensis, Prunus nepaulensis predominating. . First plantations were raised here way back in 1892. The plantations are stocked with Dhupi (Cryptomeria japonica) mixed with Arupate, Pipli, Cha mp, Kapasi, Buk, Saur, Kawla, Utis, etc. Scattered plantations of Hemlock (Tsuga brunoniana) and pure plantations of Dhupi also occur.
Barking deer and wild pigs are distributed all over the sanctuary. Goral and serow occupy the undisturbed valleys and steep ridges while the Himalayan Black Bear comes down from higher' elevations elsewhere and stay during autumn and to winter. .Leopard, jungle cat & leopard cat occur in lower elevations.Common Rhesus,Assamese Macaque, Indian civet, Himalayan Flying Squirrel, Scaly Ant-eater,
Himalayan Jackal and Wild Dog are found here. The area is rich in bird life. Large yellow naped wood-pecker, Tickel's Golden back Wood pecker, Emerald Cuckoos, Black-backed KhaJij Pheasant, Red Jungle Fowl, Hornbills, Imperial Pigeons, Green, Pigeons, Thrushes, Babblers, Sunbirds etc. are found.