You may want to have a look at these maps.
http://www.angelfire.com/tx/missileaway/
Also, try and find yourself a copy of this book.
Nuclear Heartland, A Guide to the 1000 missile silos of the United States.
Also look at these websites.
http://w3.uwyo.edu/~jimkirk/mx.html
http://www.siloworld.com/COORDINATES/LOCAL.htm