Between 100 and 190 unconventional wells are drilled per year in the Neuquén Basin targeting the Vaca Muerta Formation. Between 7000 and 13000 tons of sand are used per well, representing 15-20% of the total cost of the well. The sand has been traditionally mined in the Entre Ríos and Chubut provinces, located far away from the basin, thus generating an added cost in transport and logistics. However, in the last years, fracture-quality sands have been found in the nearby Rio Negro Province, representing a major savings in the transport cost. The accumulations are in Holocene alluvial/colluvial and eolian sediments deposited in the endorreic basin of the Bajo de Menucos/Salitral de Santa Rosa. The sands are well sorted suarkoses, have roundness and sphericity above 0.6 in the Krumbein scale, and contain up to 12% of plagioclase/ feldspar. These sands have lower resistance to crushing than those from Entre Ríos, but it is estimated that their properties are good enough for hydraulic fracturing. It is postulated that these sands are derived from the erosion of the Santonian quartz-rich fluvial sandstones of the Bajo de la Carpa Fm., which were derived from the acidic volcanics and granites of the Nordpatagonian Massif located to the south. This unit was eroded during the formation of a Pleistocene pediment and these sediments were later reworked again during the Holocene resulting in the deposition of fracture-quality sands. Given the large areal extension of these sands, it is estimated that the available volume is more than enough to supply the development needs of the Neuquén Basin.