Geoelectrical investigations in Grundy County of northwestern Missouri where the groundwater resources of the glacial deposits have already been examined through an extensive drilling program by the Missouri Geological Survey and Water Resources, indicate that water-bearing gravel deposits can be distinguished from glacial deposits containing appreciable amounts of clay and limited amounts of water. The Schlumberger method used for the geoelectric depth soundings in the vicinity of the Survey's drillholes demonstrates the exploratory usefulness of the method in that it can partly replace the more expensive procedure of drilling. The method also provides improved interpretation between drillholes. Results of the investigation show that, in the area, clay has a resistivity below 20 ohm m, that the fresh water-bearing gravel at the bottom of the buried glacial stream channels has a resistivity of 40 to 50 ohm m, and that the near surface glacial gravel deposits have a resistivity above 100 ohm m. (Author Modified Abstract)