Thursday, December 23, 2010

Downloading USGS Topographic Maps

I have prepared topo maps for each area, but the resolution ends up being a little low to make the file sizes manageable for emailing and downloading. If you would like to have your own, unedited map, you can download the 7.5-minute maps for free on the USGS website. They range in size from 4.7 mb to 7.4 mb.

The simplest URL is http://store.usgs.gov. Then to actually download the map you want, follow these directions:

1. Click on the Map Locator link (center right)
2. Type "atascosa peak, az" in the search field and click on Go
3. If you click on the red pushpin on the map, a window will pop up with a link to download the 7.5X7.5 map for the Ruby quadrangle.
4. If you click anywhere else on the map, a new red pushpin with appear, which you click on to again download that 7.5X7.5-minute map. It will be a different map only if you click in a different quad (outlined in black and names are highlighted in yellow)

The AZAH Circle straddles eight different quads: Arivaca, Murphy Peak, Tubac, Bartlett Mountain, Ruby, Pena Blanca Lake, Alamo Spring, and Pajarito Peak. I created the maps by downloading all 8, making one giant map on Photoshop Elements, then drawing the circle using the drawing tools. I then cropped out each area and resized them.

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