USGS Digital Raster Graphic (DRG) Files

A Digital Raster Graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is georeferenced to the surface of the earth. DRGs are offered in the original USGS designated coordinate system of Universal Transverse Mercator (UTM) Zones 15 and 16 (with map collar) and also the entire state in UTM Zone 16 (without map collar; they provide a well-known, large-scale, digital base mapping layer. Learn more about USGS DRGs.


Data Distribution: Uncompressed Data

Data files are offered as original USGS DRG .tif files. One uncompressed file is roughly 4 megabytes in size.


A statewide collection of 1:24,000 scale quadrangle data requires about 2.6 Gigabytes of storage space. We do not plan to distribute uncompressed data files by any other means (cd-rom, zip drives, portable drives, ftp download, etc).

USGS DRG data for Illinois are available free-of-charge via:
a list of 1:24,000 scale quadrangles (1,071 files) for data download,
a list of 1:100,000 scale quadrangles (51 files) for data download, and
a list of 1:250,000 scale quadrangles (17 files) for data download.

    Uncompressed .zip file bundles contain:
README.txt - a text copy of this file listing,
<filename>.tif - TIFF image,
<filename>.tfw - Companion Georeferencing file,
<filename>.fgd - The original USGS metadata, and
<filename>.updated.met - IDNR modified metadata.

Metadata:
Sample original USGS 1:24,000 quadrangle metadata for UTM data by zone.
Sample original USGS 1:100,000 quadrangle metadata for UTM data by zone.
Sample original USGS 1:250,000 quadrangle metadata for UTM data by zone.

Note: the USGS changed the name of the 1:24,000 Eaton Quadrangle to Porterville.

File index:
The USGS Topographic Map Index (5.2 MB) can assist you in locating a 1:24,000 scale quadrangle.

1:100,000 and 1:250,000 scale quadrangles are in tables that approximate the shape of Illinois.

Data Distribution: Uncompressed Data

An ArcIMS web service is being created from the original 1:24,000 scale quadrangle GeoTIFF files loaded into ArcSDE.


Project Support for Data Distribution

Project funding was contributed by the Illinois Council on Food and Agricultural Research (CFAR) Strategic Reseach Initiative and the Illinois Geographic Information Council.