Solving the mystery of the old fence line trees in Hubbard Park led me to another mystery nearby. As I was snowshoeing down from the park, I came across the excavations by a woodpecker, probably a Pileated Woodpecker, in a Red Pine tree.
The mystery is the unusual markings around the holes, most clearly visible on the most recent but also visible on the two older ones. While I’m by no means an expert, I’ve got feelers out to several who are to see what they might know.
Here are two photographs with a bit more detail:
I love seeing things like this that remind me both of how little I really know and also of what an exciting mystery life can be!
Still Learning To See 
Bryan Pfeiffer might be able to answer your questions. Maybe he is one of the people you have contacted. Vins I believe may have his e-mail address and/or phone number.
Yes, I’ve been in touch with Bryan and he thought “Pileated!” But the lucky guy is in the Grand Canyon beyond email so no more details.
I’m voting “pileated,” too. I’m not a bird expert, but we had pileated woodpeckers in our back yard in Ohio, and they left square holes like this in our trees.
Yes, all seem to agree to the holes being made by a Pileated. The mystery is the horizontal lines.
Just today, I have seen marks like this on a tree (but without a whole) and wondered what they were. Maybe the bird was hunting for magots under the bark? Maybe it was searching for a softer spot? In any case, it looks interesting.
Maybe it is just a way to remove the bark. It is first removed in stripes and then the remaining bark in between can be peeled or hacked away.
Fascinating!