workyard -> deposit time N/A

I have a hardwood cutter in zone 6 complaining about lack of tree's while there are plenty of hardwood tree's around him (see attached pic)
the cutter next to him does not have this problem.
the walking time is displayed as N/A, so i assume its some thing with the exit of the cutter being in mountains or so.

I've found that there are several fir trees on the map that are never cut, kind of annoying.
the trees on isle i don't mind so much (although they could lend the fishing boat) but the cluster on the border of section 2 and 5 keeps annoying me.