For the purposes of our survey, VBS has divided Vermont into 1,104 blocks of equal size (each about 3 miles x 3 miles). We've randomly selected 184 of these blocks for the focus of our survey work. We call these blocks "priority blocks." They make up a representative sample of the Vermont landscape. No one is ever far from a priority block And you can download a map of any priority block from the VBS web site.

• If you already know the name of a given priority block, you can download it from VBS Map Downloads.

• If you'd like to adopt a priority block you can find it and download it at the VBS Survey Block Map Page.
  
  
• You can use the free Google Earth mapping program to view survey priority blocks. Download block file and open in Google Earth.
  

Once you know the name of your VBS priority block, you can purchase a United States Geological Survey Map that includes your block. The map you'll want to buy has the same name as your prority block name.

USGS maps are sometimes available from certain office supply shops, camping stores, and sporting good retailers. Here are some suggested locations:

• List of Vermont Merchants
• The Vermont Geologic Survey
• USGS Office (can be slow to fill orders)

A VBS priority block is actually one-sixth of a USGS topographic map. So in order to locate the priority block on your USGS map you must first divide your map into six blocks of equal size. Bisect the map vertically with a single pencil line (measure the midpoint as accurately as possible). Next divide the map horizontally into thirds. Number the six resulting blocks 1 through 3 down the left side and 4 through 6 down the right side. Consult the VBS Manual for Volunteers (Appendix II) to determine which of these resulting six blocks is the priority block for your USGS quadrangle.

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Additional Sites with Helpful Maps

Vermont Wildlife Management Area Maps
Vermont Agency of Natural Resources Map Page
Vermont Center for Geographic Information
Vermont Mapping Program (Digital orthoquads, which are fancy aerial photos.)
USGS National Map Viewer
Topozone (Online topo maps and latititude-longitude information)

How to Read the Priority Block Maps

Below is a sample map of a priority block. It contains the priority block boundaries in red any public conservation areas in orange, as well as a standard topographic map features. You might use the map simply to determine where to survey - often openings shown in white. You can also use the grid on the map to locate the position of a butterfly you photograph or collect during your survey work if you are not using a GPS. If you see an Eastern Pine Elfin while surveying behind Thetford Academy, for example, you can use the grids to calculate its approximate position to include on the survey's Voucher Data Card. In this case, the Eastern Pine Elfin would be located at 146139 x 521516.The grid is Vermont State Plane Meters, which is standard for all state computer mapping data. There are 500 meters between each dotted line across the map, with tick marks on the margins indicating 100-meter intervals.

Downloading Priority Block Maps