Great photo Jos!
It was a Giant Burr Oak tree. My wife and I are looking for a new house this summer, I was thinking about getting a seed from the witness tree nearby here and plant it in the back yard, if we get a backyard that's big enough.
Thanks! When looking at these, I was struck with fact that those who made and used these have been gone for a century or more.
Sounds like you've thought about this issue long and hard.