The primary objective of the SouthernGobi Regional Environmental Assessment (REA) is to provideguidance for sustainable management of environmentalresources in the future development of the Southern GobiRegion (SGR), development that will be led by rapidexpansion of mining. The REA defines two developmentscenarios-a base-case and a high case-and explores theirdirect and indirect impacts on the natural environment,taking into account the opportunities, constraints, andvulnerabilities of the Gobi natural systems; the individualand cumulative direct environmental impacts and potentialindirect impacts of the planned development; and, at ageneral level, the institutional capacity to manage theimpacts. The REA target audience includes governmentofficials at central, regional, and local levels; privatesector investors and the consultants who are engaged forproject design and environmental impact assessment;development finance organizations; and Mongolian civilsociety. This report was discussed in draft form atstakeholder workshops held in Ulaanbaatar and Dalanzagdad inApril 2009 and has been revised to reflect commentsreceived. Thanks are due to all those who joined thosediscussions. The report draws on information from workshopsheld in Mongolia, in May, September, and October 2008, and afield mission to the Southern Gobi Region in November 2008.Other information was obtained from various mining companiesin Mongolia including Ivanhoe mines Mongolia, Inc., and itsconsultant Eco Trade; Rio Tinto; Energy Resources LLC; andSouth Gobi Sands.