When does a unit go "under" an entrenchment?

[plloyd1010]

I would give the entrenchment modifier. You me, the hex terrain is entrenchment, no matter what is printed on the map. So, you get the benefit as soon as you enter. As was pointed out above, you get woods terrain right away, so why not entrenchment.

That actually doesn't make a lot of sense in the context of the rules.