Near the town of Bario (also known as "Bario Asal"), the prayer mountain is located near the Arur Dalan village while the salt spring is located near Pa Umor village. The exact origin of the salt spring is unknown. However, several hypotheses have been proposed. One stated that fresh water carries salt from clay particles which is found abundantly in shale and mudstones. The soils at Bario are derived from accreting and non-accretin alluvium, consists of poorly drained clays, podzolic sands, and organic soils. Water-logged soils are suitable for rice cultivation, while better drained non-accreting alluvial soils are suitable for vegetables and citrus fruit cultivation. Bario valley has frequent flash floods because of steep mountain ranges and high surface runoffs. The Bario Asal is drained by four small streams of the river with one to four metres in width, which converge into Dappur river, one of the main tributaries of the upper Baram river. Some research pertaining to Rainfed lowland rice in Sarawak has been reported