Weston River is part of the largest wetland (Klias Peninsula) in Sabah. Wetland is a generic term that covers different aqua-ecologies such as coastal areas, river, lakes, mangrove, peat swamp, nypa swamp, etc., and it is the important habitat for some endangered Borneo wildlife such as Proboscis Monkey. The Nipah forest along Weston River is in great shape. Nipah trees grow very well in estuary, where sea and river meet, sometimes they are even dense enough to form a mini island in the river. Locals use the leaves of Nipah Palm to make roof and its sap to create sugar.