Estimating log diameter up a tree

[caveman]

On a 25"x 1/4" thick Biltmore Stick, at 66' away from the tree, if aiming the stick like a rifle, the 8" top of the tree will disappear behind the 1/4" thick end of the stick.  On longer, 5/16" thick Biltmore sticks (that measure five logs instead of four), a 10" top will disappear when done the same way.  

This is not exact but on a tree that does not have a lot of taper, no obvious "cut me here points", this is a decent method to estimate 8" and 10" tops.

[customsawyer]

Are we looking at hardwoods or softwoods? I'm also on the side of marking extra trees for the ones that you miss with the estimates or get bent when they hit the ground. When you start cutting and sawing  them go for the biggest and longest ones first. If they fail to make a big or long one then the can make some of the smaller or shorter ones on the list.

[Don P]

What he is wanting to see is basically enough trees marked to do the frame, then enough stumps to feel confident you weren't buying ungraded timber in. You won't be arguing over one stump this way or that.
NC is more of a homestead exemption than a grading exemption when you compare the language to other states. He's being somewhat picky, but for a reason.