Seismic hazard assessments depend on an accurate prediction of ground motion, which in turn depends on a base knowledge of three-dimensional variations in density, seismic velocity, and attenuation. The datasets here are components of a National Crustal Model that couples geologic characteristics and geophysical parameters using a physical theoretical foundation combined with measured data for calibration. The model is intended to be internally consistent and seamless on a national scale; care is also taken to maximize consistency with existing regional models. An initial version of the model components are defined for the western U.S. on a 1-km grid. While the current focus of this effort is on improving estimates of site response in seismic hazard analysis, this model can benefit other fields of research.