National Map

  1. Open by:
  2. To download data
   
  • Select available data products.  The most useful will be:
    • Land cover--but this does not have the 1992 data,  which you must get from MLRC.
    • Elevation Products (3DEP): this is 3DEP/NED in 1", 1/3" available nationwide;  and 1/9", and the 1 m DEM available in some locations.
    • Elevation Source Data (3DEP): LAS files.  These are large
    • Names--Geographic Names Information System (GNIS, or gazetteer)
  • Less useful
    • High resolution imageryWMS Maps may be a viable alternative.
      • Imagery--1 foot (HRO) .This imagery may have the choice of multiple dates, some of which will include 4 bands with IR for vegetation analysis.
      • Imagery--1 meter (NAIP)
    • NHD: you probably want the shapefiles for Dynamic Extract and Dynamic extract with flow table.
  • Select format.  If possible you want Geotiff or Shapefile as the best formats for use in MICRODEM.  In particular avoid the Geodatabase, which is a proprietary ESRI format for Arc.  Some other formats will require that that you have GDAL downloaded and correctly set up.


For the elevation data there are three formats, all of which work with varying challenges.  All will be zipped initially.

  • GridFloat will be the best option; select the .FLT file.  You also need the .HDR file, and must keep the two files together.
  • IMG is the next best choice; you select the IMG file and GDAL converts to a Geotiff which will open.
  • ArcGrid is the trickiest choice; you must use GDAL and then pick the correct  "w001001.adf" file which will be in directory called something like "grdn39w077_13".

Zoom map to show your area.

Pick the option for "Current extent" on the top of the mpa.

Find products.

For download, you can:

  • Download file by file, the easiest choice if you want just a few file.
  • You must pick the data you want and add to your cart (you use +All instead of checking each individually). Then view cart.  You can download all files together.

Download each layer individually.

You can try to use the BDA (Bulk Download Application). It may have challenges, some of which might be institutional security measures.

 

   



National Map Alternatives 

The table below shows alternatives to the National Map if the site is down or unresponsive.  These might also be faster and easier to use.  Most options now require you to get pre-packaged tiles, instead of packaging the region on demand that was possible with the Seamless Server model.

Data layer Alternative source Comments
3DEP/NED DEMs MLRC

1" and 1/3" NED, and option to get Geotiff, which is the best format for MICRODEM since it usually works without GDAL

NLCD MLRC Probably faster and simpler than National Map, which does not have the 1992 data.
Insure the program can recognize this data set after downloading and uncompressing it.
Gazetteer USGS NAMES server  
Structures   http://nationalmap.gov/structures.html  Alternative to Gazetteer for some applications.
Point clouds    

Last revision 11/2/2018