The bathymetry (bottom elevation) of the downstream lock approach and lock chamber of Peoria Lock, near Peoria, Illinois, was surveyed on September 19, 2019. The data were collected using a multibeam echo-sounder mapping system (MBMS) with integrated inertial navigation solution (INS) mounted on a manned survey vessel. The raw data were processed and gridded to 0.5 meter using elevation values computed from the Combined Uncertainty and Bathymetry Estimator (CUBE) method, which provides an estimate of the bathymetric elevation and the total propagated uncertainty (TPU) at each gridded location. The 0.5 meter grid was oriented at 39.32 degrees to north to be aligned with the Peoria lock chamber. The bathymetry and TPU data were exported as text files.