Regional grid files and 3D voxel models were used to study crustal architecture beneath the Southern Midcontinent (USA) by McCafferty and others (2019). The study covered a rectangular, multi-state area of 924 by 924 kilometers centered on Missouri, and a corresponding volume extending from the topographic surface to a depth of 50 kilometers below sea level. The grid files consist of surface grids (magnetic field observation surface, topographic surface, Precambrian basement surface, and Moho interface) used to construct templates and initial physical property models for 3D inversions, observed geophysical data grids (Bouguer gravity anomaly and reduced-to-pole (RTP) aeromagnetic anomaly) used in the inversions, and calculated geophysical data grids produced by the inversions. All grids are sampled at a 2,000 by 2,000-meter grid interval. The 3D voxel models represent the density and magnetic susceptibility of the crust as interpreted using 3D inversion. The individual voxel elements are 2,000 by 2,000 meters by 500 meters thick.