A groundwater survey of areas of Mimili Station, within and around the Everard Ranges in North West South Australia, indicates that there are reasonable prospects for finding supplies of stock water in fine grained alluvial materials which form broad valleys within and extensive plains around the Ranges. The Ranges are inselbergs of granite and granitic gneiss with cross-cutting gabbro dykes. Geophysics (seismic refraction and electrical resistivity) was used in one place to determine the profile of a buried valley. Besides the alluvium which is usually low yielding due to its fine grained nature, other possible aquifers considered were sheared zones in the granitic basement and gabbro dykes.