This report presents the results a hydrologic investigation at White Sands National Monument (WHSA) in southern New Mexico. The principle objective of this study is to develop a conceptual model of the shallow groundwater system within the gypsum dune field with the intent to increase our understanding of how it interacts with the larger, regional hydrologic system. The monument, which encompasses approximately 115 square miles, includes a portion of the largest gypsum dune field in the world.