Mountain reedbucks inhabit three separate geographic areas, each containing a recognized subspecies. Southern mountain reedbucks are found from the Eastern Cape Province to south-eastern Botswana. Throughout history some populations have disappeared in this range for various reasons. The East African subspecies (Chanler's Mountain Reedbuck) is found in Tanzania, Kenya, Uganda, Sudan, and Ethiopia. The West African subspecies has only been found in Cameroon. 

Mountain reedbucks are normally found in hilly, broken terrain with grasses dominating the ground cover. They inhabit areas with scattered trees with water sources nearby. They will use flat terrain adjacent to hilly and broken terrain. 

An adult male mountain reedbuck is about 70 cm tall at the shoulders and weighs 30 kg. The species is characterized by short curved horns. Adult female mountain reedbucks are smaller than males, but both sexes have greyish brown hair on the body, red necks, white undersides, and a bushy tail with a white underside. Both males and females also display a dark scent patch underneath the ears.

Mountain reedbucks can be active at any time of day, but seem to prefer to feed in the early morning, evening, and sometimes through the night. They are normally found in small groups of six or less animals. A typical group is made up of one adult male and several adult females and juveniles. The dominant males will tolerate younger males, but normally the younger males will form bachelor groups and live on the outside of the herd. The dominant males will mark their territory using visual displays, olfactory, and auditory signals. Once these territories have been marked they will normally remain there for the whole year. 

Mountain reedbucks will use a shrill whistle to indicate danger nearby. They will also use a whistle to warn other animals off its home range along with scent and visual displays.