Using the horizontal-to-vertical spectral-ratio (HVSR) method, we inferred the depth to bedrock at the Slate River Floodplain, CO, USA. The point-scale passive seismic data were collected using Model TEP-3C Tromino seismometers over 20 min or less intervals with the instruments coupled directly to the floodplain ground surface at 42 non-flooded locations during June 2021. The ratio of horizontal-to-vertical Fourier spectra (HVSR), determined using Grilla software (MOHO, S.R.L.), along with the estimated sediment shear-wave velocity, was used to calculate the depth to the bedrock contact. This passive seismic dataset indicates that the deepest bedrock is 16 m below the surface, while the bedrock reaches the surface at the hillslope. This release contains the inferred bedrock depths based on likely shear wave velocities (Vs) intrinsic to the underlying sediment, ranging from 300 m/s to 400 m/s, listed in the processed_data subdirectory in the file 'SLAC_HVSR_June2021.csv.' The range of possible depth to bedrock interpretations is included for demonstration purposes only.