The city of Mar del Plata is located on the southeastern tip of the Buenos Aires Province within the landscape of hills and plateaus of the Tandilia Range. These plateaus are composed of orthoquartzites within a plain composed of silts and sands with volcaniclastic levels, of aeolian origin and Plio-Pleistocene age. This region has the more complete mammal remains of South America. The plain also contains fluvial deposits of Late Pliocene-Early Pleistocene ages that were dominant towards the south of the ranges. To the northeast, the fluvial deposits are either of Middle or Late Pleistocene ages. From the inventories of three collections from museums of the surroundings, a digital database of the vertebrate remains was updated and introduced into a GIS programme. The distribution of mammals in this region is explained by the variability of environments, and water and shelter availability. The abundances of fossorial specimens of different mammal families and sizes were related to the drainage design that made the caves distant from the groundwater levels. These inventories and GIS procedures subject for easy updates were applied to understand geographic and environmental distributions.