Downloading topo maps without opaque overprints from US Forest Service

James G Smith

USGS Volcano Hazards Program

April 27, 2015

Digital versions of U.S. Geological Survey 7.5’ topographic maps without opaque overprints are available from the U.S. Forest Service. However, only topo maps that include U.S. Forest Service land are available.

USFS topographic map information is available in 3 different formats: “geo-enabled PDF, GeoTiff, and Vector data. GeoTiffs and PDF's can be downloaded from the FSTopo Map Images page.” (Source: http://data.fs.usda.gov/geodata/vector/index.php) Don’t get your hopes up for vector contour lines. The web page referenced just above states, “FSTopo downloadable vector data does not include contours or woodland tint for conterminous US.”

All USFS topo maps have USFS road numbers, a light brown tint for lava and a very light gray over print for non-USFS lands inside Forest Service lands. Water polygons are shown in blue and marshes are shown with the standard pattern. Contour lines and other information are easy to see in overprint areas. One bug reported by a colleague, “Depression contour lines have no barbs.”

Projection (For the northern California maps I checked): NAD83. Datum: Universal Transverse Mercator, zone 10

Roads marked with USFS road numbers. Roads are symbolized as “Highway”; “Road, Unspecified”; “Road, Paved”; “Road, Gravel”; “Road, Dirt”; and “Unimproved, 4 wheel drive”. Roads in National Forests are further classified as: “National Forest, suitable for passenger cars”; “National Forest, suitable for high clearance vehicles”.

Roads beyond barriers and locked gates are not shown on the maps.

Directions for downloading USGS topo maps without overprints from the US Forest service

* Start at http://data.fs.usda.gov/geodata/ (USFS Geodata Clearinghouse). On this page…

* Click on the small image of a US map part way down the page on the right. A new page opens.

* On this new page in the frame at the upper left (FSTopo Map Images) click on the link “topographic maps”. The next page opens showing a map of the United States with USFS lands shown in green.

* There are several ways to zero in on the area you are interested in. The easiest is to click on a state which brings up an interactive map of the state you chose showing a 1 degree by 1 degree grid and each National Forest in a different color. If there is no USFS land in a rectangle there are no maps.

* Click on the 1 degree by 1 degree rectangle containing the area you want. The next page opens showing both a list of maps (ordered by the map number with the map’s name next to it) and an index map (Hovering over a point on the index map brings up the name of the topo map). There two tabs for downloading two different types of maps “PDF maps” and “GeoTiffs”.

PDF maps open in Adobe Reader. The PDFs have a collar with all the usual collar elements. If you want a full sized hard copy chose this option. Use “GeoTIFFs” for ArcMap because the GeoTiffs use indexed color so you can turn the white background transparent. However because the raster is so fine grained viewing it in ArcMap at a scale smaller than 1:24,000 is difficult.

* For PDFs select the “PDF Maps” tab, then click a map’s name. (A list of layers that can be turned on and off on is shown at http://data.fs.usda.gov/geodata/rastergateway/products/geoenabledpdf.php but I’ve not figured out how to do this). The PDF opens on your screen.

* For GeoTiffs, select the “GeoTiffs” tab, then click a map’s name. A zipped folder is saved in your Downloads folder. The topo map’s name is the same as the map you clicked on. (These instructions are for a PC).

* Unzip the contents of the folder and then move the folder to ArcCatalog from your Downloads folder.
There are two tiffs in this folder: The tiff with a label of “xxx_geo.tiff” is collarless. The one labeled “xxx.tiff” has a white border around it but no information in the collar. Both use indexed color.