The DEM to mountain transformation was implemented in the Globe DEM representation of Zagros Ranges in south Iran, where collision of the Arabian shield with Iran has produced a spectacular mountainous physiography. An object partitioning framework of the landscape was defined on the basis of the mount and the non-mount terrain classes as well as the isolated mountain features. A parametric representation was achieved on the basis of geomorphometric parameters related to elevation and gradient. Descriptive statistics, frequency distributions and the linear regression between attributes were used in an attempt to characterise landscape. Finally, a terrain classification scheme based on cluster analysis was implemented and the landscape of the study area was mapped on the basis of mountain geomorphometry. From the geomorphometric point of view, Zagros Ranges was proved to be an uplifted landscape, equally developed in the whole elevation range with only one major peneplain at the sea level. The terrain was sloping vertically to the main axis of the mountain ranges while the asymmetry observed towards SW was interpreted as the result of the collision of Arabian shield to Iran. The linear regression between local relief, gradient and size of the mountains captured the geometric signature of the study area. The centroid clustering method revealed clearly the SE–NW stair-step topography observed in Zagros Ranges while the steepest and more massive mountains were also observed along this direction. The zones derived by the mapping of clusters were associated to the existing morphotectonic zones of the study area while geomorphometric processing proved capable of segmenting morphotectonic zones to sub-regions with different geomorphometry.