Bill V is the winner!
Black Walnut GOLD!
My buddy, who just started renting a house, didn't know how long the tree had been cut, but figured it was at least a year already. He's actually helping the owner fix the house up and they were just going to haul it to the dump. The bark that was still on, which was most of it, came right off and had cool stuff growing under it. It's possible it came down in a windstorm a few years back, or at least most of the tree did.
The combined weight of those chunks has to be over 600 lbs. If I can sneak it outside, I'll use the wife's bathroom scale to weigh them because I want to know. Those are roughly two foot lengths and the big ones took quite a bit to get them in the truck.
This came from a well established neighborhood and I tried counting rings but have to clean it up a bit before I can get the whole pic. In one spot at about mid radius I was counting 14 to the inch.
My plan is to try and turn a bowl today after chores. I'll post some more as I go.