Nokrek Biosphere Reserve is located in the Garo Hills district 2 kms from Tura Peak. The reserve is one of the least disturbed forest tracts of the sub-himalayan ranges. It is the first biosphere reserve of its kind in the northeast region. The Garo Hills contain many natural limestone caves. The famous Siju Cave is located very close to the Nophak Lake near the Simsang River game reserve. The Cave is filled with water and is miles long.

Geology, rock and soil
The entire Biosphere Reserve is hilly. The rock is mainly gneisses, granulites, migmatites, amphibolites and banded iron formation, intruded by basis and ultra-basic bodies. In most of the Biosphere Reserve area the soil is red loam. But sometimes it varies from clayey to sandy loam. The soils in the Biosphere Reserve are rich in organic matter and nitrogen but deficient in phosphate and potash. The area consists of patchy sedimentary rock comprising of pebble bed, sand stone and carbonaceous shales.

Fauna
Nokrek Biosphere Reserve supports a wide variety of animals. There is a great diversity of animal species like mammals, reptiles, avi-fauna and invertebrate groups. Detailed scientific study on fauna is lacking.