The Eastern Kanuku Mountains and the Western Kanuku Mountains are separated by the Rupununi River.
The lowland forests sustain 60% of all the known bird species in Guyana. 150 mammal species, or 80% of all mammals found in Guyana, live in the Kanuku Mountains. Prominent species include the Giant otter, the Harpy eagle and the Arapaima. The Kanuku Mountains rise to almost 3,000 ft.
Concern for the fate of the wildlife of the Kanuku Mountains was raised by the recent completion of the road system linking coastal Guyana with the interior and the Brazilian frontier. The road passes close to the Kanukus and is a potential source of unsustainable resource exploitation.