Background hydrologic data were collected from 1988 to 1993 in the Fristoe Unit of the Mark Twain National Forest. Water-quality data collected from area streams, springs, and wells were analyzed using trilinear diagrams, stiff diagrams, boxplots, and summary statistics. The water is a calcium- magnesium-bicarbonate type. Streams generally have slightly larger potassium, barium, and total organic carbon concentrations than spring or well water. Well water has larger bicarbonate and zinc concen- trations and larger variability in sodium, chloride, and nitrate concentrations than stream and spring water samples. The bulk mineralogy for streambed material is primarily coarse grain quartz. Quantitative elemental (chemistry) analysis on the less than 63 micrometer fraction of bulk material was performed. The heavy mineral concentrate in the streambed material was analyzed using semi- quantitative optical mineralogy and 37-element semi- quantitative emission spectrography. Water levels were measured in 57 area wells in the spring and fall from 1990 to 1993 to determine ground-water level fluctuations. Ground-water fluctuations ranged from less than 1.0 to 205.1 feet in these wells. Continuous water-level recorders were installed on three area wells. Depth to water ranged from 289.68 to 333.39 feet in the lower Eleven Point well, which is completed in the Ozark aquifer. Depth to water ranged from 78.73 to 90.20 feet in Ozark Lead Well 1 which is completed in the Ozark aquifer and St. Francois confining unit. Depth to water ranged from 127.53 to 135.67 feet in Ozark Lead Well 2, which is completed in the St. Francois confining unit and the St. Francois aquifer.