Sikkim is a part of the Eastern Himalaya.
The Eastern Himalayas are situated between the Kali Gandaki River in Central Nepal in the west and Myanmar in the east , occupying southeast Tibet in China , Sikkim , North Bengal , Bhutan and North-East India . Larix griffithii , the Sikkim larch , is a species of larch , native to the eastern Himalaya in eastern Nepal , Sikkim , western Bhutan and southwestern China ( Xizang ) , growing at 3000 -- 4100 m altitude . Sikkim ( [ ˈsɪkᵻm ] ) is a northeastern state of India . A part of the Eastern Himalaya , Sikkim is notable for its biodiversity , including alpine and subtropical climates , as well as being a host to Kanchenjunga , the highest peak in India and third highest on Earth .