Friday, April 15, 2016

How to Display USGS Quadrangle Map Coverage in Google Earth



Have you ever wanted to locate the topographic map that shows the area you're interested in? If so, you can download a .kml file that will display an overlay in Google Earth that shows the areas covered by the various United States Geological Survey (USGS) quadrangle maps.

The helpful file in question is called QUADS and is available for free from the same people, Metzger-Willard, who offer the PLSS overlay file for Google Earth discussed in the previous post.

Once you have Google Earth – I recommend the Pro version as it is now free at the link here – navigate to USGS Quadrangles and click on the QUADS link in the box near the top of the page. After the file downloads, open it in Google Earth as described in the previous post about the PLSS overlay file.

To use the overlay file, navigate to your area of interest in Google Earth. In the left-hand sidebar of Google Earth, check the “Search Results” box in the “USGS Quadrangles” section. (You may have to expand that section to see the “Search Results” and other option boxes.) Check the “Automatic” radio button under “Refresh Mode” and an overlay of the available quadrangle maps will appear in the Google Earth display.



If you click on one of the colored dots in the center of the various map outlines displayed in Google Earth, a pop-up box will open that gives the name and other information about that particular map.



Clicking the “All maps with this name” link in the box will open a new page in Google Earth with a list of all available maps of the selected area together with their dates and links for downloading them as PDF files.



If you want, you can display a topographic map overlay of the area you are viewing in Google Earth by clicking the “TopoMaps” radio button in the “Overlays” section of the “USGS Quadrangles” section in Google Earth's left-hand sidebar. In my own experience, these overlay maps are not that detailed or useful. I find that downloading the maps I want from the pop-up box links mentioned earlier is more satisfactory.

I hope the information above helps you find the maps you need for your prospecting activities. As always, feel free to ask any questions in the comments section below the post. I will do my best to answer as soon as possible.


Happy prospecting!

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