I keep a little map of magnetic variation in my PSK. There's around a 40-degree variation across the continental U.S. Here are some links with info and maps:
ttp://www.geolab.nrcan.gc.ca/geomag/compass_e.shtml , http://www.thecompassstore.com/decvar.html , and http://www.windtesting.com/4.html .

Steve
_________________________
"After I had solaced my mind with the comfortable part of my condition, I
began to look round me, to see what kind of place I was in, and what was
next to be done"