Thanks guys, I appreciate the information.  I recently looked at a number of poles while planning a grain bin move.  I don't recall seeing any that didn't have the "6", but this is mostly "old" line.  I wondered if the "6" was the recommended depth or what, as I knew the poles were marked long before installation.

How common are the tree farms and where are they usually located.  It is ashame that so many of our natural pine tree stands are being destroyed by the pine beetle.  Much of that lumber will never be salvaged with no effort to save.  I guess that is nature's way - but so is huricane damage to coastal lands.