continually updates its 7.5' topographic map series
for the entire nation. In order to keep up with the
times, the USGS is now providing the maps as DRG. Recently,
the USGS, via the Louisiana
Department of Environmental Quality, has provided
the latest DRG updates for Louisiana to Atlas. The new
DRGs are in Geotif files with accompanying tfw files.
FGDC metadata for each DRG gives important information
such as when the DRG was updated.
updated DRG files are available through the 1:24,000
DRG Downloader. The 7.5' quadrangles with updated
DRG files are shown in the downloader's index map in
a lighter shade of green. The downloader gives the user
the ability to download the pre 1998 DRG or the post
1998 DRG. As more of these updated DRGs become available,
they will be added to Atlas.
table below gives the differences between the previously
available DRGs and the new, updated DRGs.