Digital Topographical Maps
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Digital Topographical Maps |
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PENNSYLVANIA HISTORICAL TOPOGRAPHICAL MAPS CDROM |
VIRGINIA HISTORICAL TOPOGRAPHICAL MAPS CDROM |
Delaware New Jersey Rhode Island HISTORICAL TOPOGRAPHICAL MAPS CDROM |
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What are Digital Topographical Maps? |
| Digital maps are electronic copies of scanned paper topo maps. You can download and save these digital maps to your computers hard drive for your personal use to access anytime. They look just like the topo maps you may be used to. These files can be quite large, often around three megabytes in size, and can quickly fill up your hard drive. These maps come in various scales. |
| I recommend getting the 7.5' or 24:000 scale maps. These have more detail on them, but cover less area. To use these maps, you will need a viewer. A free simple viewer is available from the USGS and is called "DLG Viewer". This is just a viewer, you cannot modify or save the maps. Get the USGS DLG Viewer here: http://mcmcweb.er.usgs.gov/viewers/dlg_view.html |
| If you want to add features to your topo maps, you will need software to edit the files. I recommend "Paint Shop Pro". This is shareware and you can download a free trial copy here: http://www.jasc.com With PSP, you can add text, lines, curves etc. Another feature is you can copy portions of a map and paste it into another document. |
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What can I do with digital topo maps? |
| Having your own digital maps can be very useful. With your own maps, you can zoom in on a certain area and print
it. This allows you to enlarge an area of the map. Then you can take this printout into the field with you. In the field, you can add notes or other features to the field map. Using an editor such as Paint Shop Pro, you can edit your digital maps and add the notes and features from your field map. But the main use of topo maps is the features on them. |
| This means to just manually review a topo for sites. Yes it is time consuming, but it works. Remember, a lot of sites are NOT listed in the GNIS database. Just start in the upper left and work your way to the right. Upon reaching the right map margin, go back to the left and repeat until you cover the entire map. It helps if you divide the map into grids with a pencil and ruler (paper), or add a rectangle with Paint Shop Pro to digital maps. |
| Circle possible sites in pencil and a note in the map margin. Look for old roads, schools,cemeteries out in
the middle of nowhere, (they stay but churches disappear), parks ,lakes etc. (See clip of map edited with Paint
Shop Pro below). Take the time to review and study them and look for places to hunt. You will be very surprised at what you may find. |
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Where do I get Digital topo maps? |
| There are a number of web sites on the internet where you can download for free or buy digital topo maps. I have links here to free scanned topo maps. These are the states I have found, not all states are represented. |
| Order Pennsylvania Topo Maps CDROMS |
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Determining Which Maps You Need |
| Go to the USGS site where you can use several different methods to determine which quadrangle covers your area of interest. |
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If you want paper USGS topo maps, you can find a dealer near you here: |
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Edited Map Sample |
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