The Gumpal Association is extensive in the Lahad Datu and Tawau Districts, notably in the Dent Peninsula and in the catchment areas the Bole, Brantian, Gumpal, Merotai and Tingkayu rivers.
It occurs on hills and mountains with steep slopes, often greater than 25°, and narrow ridges. Landslips are common. The soils are formed mainly on slump deposits consisting of sandstone, mudstone and tuffaceous rocks, other rocks such as chert and various igneous rocks may be locally dominant.