In the Siwalik region of South Asia, palaeolithic sites occur in varying geological contexts and typo-technological modes. Pleistocene hominid behavioral patterns and their dependence on Siwalik palaeo-landscapes are indirectly reflected through site and artifact densities, raw material exploitation, and site location. This session attempts to demonstrate the degree to which site-formation processes (including occupational and post-occupational processes), combined with modern environmental observations, can tell us about broad ecological and technological adaptations and potential mobility patterns. A hypothetical settlement-system model is presented where hominid groups were induced to move to and occupy sites with (more) stable landforms and a continuous source of water and raw material. This model has been constructed primarily on the basis of palaeoclimatic fluctuations, raw material availability, seasonal streams, tectonic regimes, typo-technology, and from associated intermontane- valley sedimentary features. This presentation also describes the natural processes and anthropogenic activities that affect the archaeological integrity of prehistoric sites in this region.