GIS Data for South Dakota
Free GIS data resources exist, but they’re very difficult to find and are generally the wrong format for Arcview. It seems that there are a number of GIS programs that each use proprietary formats. Arcview includes an executable "Import" function to convert parent data to Arcview compatible data. The "Import" function is very easy to use. On my computer, it’s located in the following directory:
C:\ESRI\VCampus\ARCVIEW\BIN32\import
DEM
USGS has created Digital Elevation Models that are provided in SDTS format. Arcview needs these files converted to .DEM to import using the Arcview Spatial Analyst. We weren’t provided with the extension, but help is located here:
http://software.geocomm.com/translators/sdts/
DEM files contain a sampled array of ground elevations at normally spaced intervals in the raster form. 7.5min blocks consist of 30m x 30m data spacing with UTM projection.
U.S. List:
http://www.webgis.com/terr_us75m.html
Obviously, click on South Dakota for South Dakota maps.
LULC
WebGIS also supplies Land Use and Land Cover data files. These describe the vegetation, water, natural and cultural features on the land surface. These maps are provided by the USGS as shapefiles in either UTM or Lat/Long. U.S. list:
http://www.webgis.com/lulc_shplatlong.html
DLG
WebGIS also provides Digital Line Graphs for the majority of the United States. There
are separate maps for boundaries, hydrography, hypsography, public lands, and transportation. They are provided in either UTM or Lat/Long. The files are in shapefile format, but I’m unable to load them in Arcview. U.S. List:http://www.webgis.com/dlg_shplatlong.html
STATSGO
State Soil Geographic soils data is compiled by the USDA Natural Resources Conservation Service. I found a nationwide soils dataset that’s downloadable by individual states. These files need to be modified using the Import function before they can be loaded into Arcview. They use NAD27 datum and are in meters. U.S. List:
http://www.soilinfo.psu.edu/index.cgi?soil_data&statsgo
DOQ, DRG, DEM, DLG
http://www.sdgs.usd.edu/register/index.html
There are DOQ, DRG, DEM, and DLG in multiple scales and years. Registration is reportedly free, but it takes a while to be approved.