A shrinking distribution

The saola may be a relict species, whose distribution and habitat has been reduced into the present small range by severe climactic shifts during and following the Pleistocene. The species may have been formerly distributed in wet forests at elevations below 400 m, but these areas in Vietnam are now densely populated by people, and are degraded and fragmented. In Lao, there is no wet forest at low elevation.

Current Population and Distribution
In Vietnam, the saola population was originally estimated at a "few hundred" individuals although this figure is now thought to be too optimistic. In 2001, the Lao population was estimated to be between 70 and 700 individuals, with current estimates favouring the lower range of this figure. There is strong indication that the saola has been experiencing a shrinking distribution for the twenty years until 1995.

Saola are distributed in scattered locations in the Annamites, along the northwest-southeast Vietnam - Lao border. In Vietnam, the species is distributed from the Ca River in the north to Quang Nam province in the south, but its exact limits are not clearly understood.

Within this area, distribution is patchy. In Lao, there are confirmed reports of the species in the southern part of Nakai-Nam Theun NBCA (National Biodiversity Conservation Area). Reports of saola south of this area include Quang Binh, Quang Tri, Hue and Quang Nam in Vietnam and Sekong in Lao.