The tamaraw was first documented in 1888 on the island of Mindoro. Before 1900, most people avoided settling on Mindoro due to a virulent strain of malaria. However, as anti-malarial medicine was developed, more people settled on the island. The increase in human activity has drastically reduced tamaraw population. By 1966 the tamaraw's range was reduced to three areas: Mount Iglit, Mount Calavite and areas near the Sablayan Penal Settlement. By 2000, their range was further reduced to only two areas: the Mounts Iglit-Baco National Park and Aruyan.