One of the most recognizable and beloved map products of all time is the USGS 7.5′ quadrangle topographic map, commonly known as a ‘quad’. These maps have been available to buy in paper format for many years, and are considered a definitive reference by backcountry users, such as hikers, campers, and fishing enthusiasts. These maps are also available as PDFs, and can be downloaded from the USGS at:
http://on.doi.gov/ctQcJG
To download a map, first navigate to the area of interest using the Google Maps applet embedded in the page. Then, click the radio button near where it says “MARK POINTS”. Click anywhere on the map to mark a point. Then click on the marker to bring up a dialogue box, showing which products are available for download. Usually, you will see two 7.5×7.5 products: one is aerial imagery, dated 2011 and usually over 25MB. The other is the classic quad, generally dated from the 70s or 80s, and has a size closer to 15MB. The primary exception is for areas near the coast, where quads containing very little land are combined with their neighbors to make a 7.5×15 product – but you can still tell the imagery from the quads by the date and file size.
The download will be a zip file, which you can unpack and open in your favorite PDF reader, and print at your convenience. The quality of the digital image causes jaggies to appear at almost all scales, but the maps are still readable. I find that I can see fairly clearly at up to 150% zoom.
From here, you can download the TerraGo Toolbar, which allows you to measure and mark your GeoPDFs from within Adobe Acrobat Reader. You can also use Global Mapper to convert your GeoPDFs into GeoTIFFs, which can then be imported into a GIS as a raster image.
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