Geographically, Guyana is divided into four regions: the coastal plain, the hilly sand and clay region, interior highlands, and the Rupununi Savannah. The majority of the population resides within the coastal plain, which ranges from 28 to 77 kilometers wide and extends from the Corentyne River in the east to the Venezuelan border in the northwest. The largest of the four geographical regions is the interior highlands. This region covers two-thirds of the country and embodies four major mountain ranges: the Imataka in the northwest, the Parkaraima in the west, the Kanuku in the southeast, and the Akarai in the south. The hilly, sand and clay belt is an expanse of white and brown sands covered in scrubs and hardwood forests with hills rising to 400 feet. Bauxite, an aluminum ore, is mined within this region. The Rupununi Savannah is almost 6,000 square miles, with the Kanuku Mountains being the most biologically diverse region within the country, with over 250 species of bird life. It is also home to the jaguar and the Harpy Eagle, an extremely rare and endangered species and the world’s most powerful bird of prey.