Well, that bark in your last set of pics, second pic with the hose, is screaming Hickory. I see in the guide that the natural range of Pignut ends at the state line...doesn't mean there couldn't be one up there, though. Now, the range of Bitternut gets up into the state more, closer to you and is also common within its range, like Pignut. With the Pignut, seems like the sapwood rots pretty quickly, like what you're seeing.I ran across this in a Google search, this looks like the wood that I'm working with now. Pignut Hickory. But, that kind of Hickory supposedly doesn't grow in this area, we are about 250 miles north of it's northern range. It's some kind if Hickory though.
Looks like Green Ash has a big range and is pretty common, Black Ash a more northern range and not as common.