From abstract: Results of a reconnaissance geochemical survey of the Eau Claire Quadrangle, Wisconsin; Minnesota are reported. Field and laboratory data are presented for 565 groundwater samples, 680 stream sediment samples, and 667 stream water samples. Statistical and areal distributions of uranium and other possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed.