Glovis — View and download Landsat imagery of South Dakota (and the world) from the USGS EROS Data Center.
Digital Base Data for South Dakota — Download DLG, DOQ, DRG, and DEM data for South Dakota from the South Dakota Department of Environment and Natural Resources, Geological Survey Program.
USDA Geospatial Data Gateway - One Stop Source for environmental and natural resource data. This United States Department of Agriculture website allows you to choose your area of interest, browse and select data, customize the format, and have it downloaded or shipped on CD or DVD.
LiDAR Data- The United States Interagency Elevation Inventory is a comprehensive, nationwide listing of known high accuracy topographic data, including lidar and IFSAR, both bathymetric data, including NOAA hydrographic surveys, multibeam data, and bathymetric lidar. Users can query by county or zoom to an area of interest and print a report.