This dataset is the raster, in feet, of the potentiometric-surface map, spring 2020, Mississippi River Valley alluvial aquifer (MRVA). The raster cell size is 1,000 meters; the raster altitude data was referenced to the North American Vertical Datum of 1988 (NAVD 88). The raster was interpolated using (1) most of the available groundwater-altitude (GWA) data from wells and surface-water-altitude (SWA) data from streamgages, and (2) potentiometric-surface contours.