The proboscis monkey is found in rubber forets of Tabalong District. The forests have fresh water sources called river and/or baruh. The presence of proboscis monkey relates to the water. The monkey is likely to get closer to the water source, although no water is in it during the dry season. The evidence may be caused by three reasons. There are other water sources containing water and those are located in area that can be reached by the monkey. The preferable feeding plants are available nearby the water source. High security against attacts of predators and disturbance of human activity is guaranteed. The proboscis monkey tolerates fresh water with pH of 4,6-7,2.