A single-probe gamma density depth gauge and soil cores were used to obtain wet and dry bulk density information to a depth of 1.0 m in poorly drained soils. The bulk density data were needed in order to determine volumetric soil water content for neutron depth gauge calibration and for modeling purposes. The factory equation for the gamma gauge was evaluated with access tube soil core data, which was obtained with a hydraulic coring device, and with soil water content data from small 15-mm-diameter soil samples obtained about 1.0 m from the access tube. Soil core bulk density estimates were highly correlated to the gamma gauge results (r2of 0.85 to 0.92), and there was no significant difference between using the factory equation and an equation calibrated with field data. The small remote soil samples provided useful information for converting gamma gauge estimates of wet bulk density into dry bulk density data.