The Siwalik (Churiya) range is a fragile land system formed from sediments during the raising of the greater and lesser Himalaya. The area is considered one of the world's most important sources of the later tertiary fossils of mammals and provides a basis for much of our current knowledge about the evolution of fauna, especially primates and reptiles. The Siwaliks, ranging east to west, occupy an estimated 13; of Nepal's total land area. Recently the area has come under tremendous pressure from illegal encroachment, which has increased the degradation process, excerbated by modern infrastructure development. This document is a basline dataset for Ilam Siwalik's socio-economy, hydrology, agriculture, land use, forestry, fauna and flora and other environmental issues. It also briefly identifies specific policies to be adopted and action to be undertaken for the conservation of the entire Siwalik areas and Ilam district.