This looks more like black locust to me than black walnut. Hard to say though. The ad says it's black walnut. View attachment 185643 I'm trying to determine if it's worth my time. If it's locust then yes. But not if it's walnut.
I've been burning bw along with pine/fir this fall. It burns just fine. It just doesn't last long. It dries quickly though. I'm not going to drive to the location to get walnut when I can get better woods in, well, my wood lot. Now if it was locust, then I'd go. Typically if it's locust in Milwaukee, it's honey locust. Carrying a CC pistol while loading rounds isn't the easiest.
Black walnut. It's decent firewood. So easy to split and dries faster than silver maple... Not as much outgassing though. Are you heading into the big city? Wood fishun? Where? If it's the tree guy on the northish side of the city who dumps the wood he can't give away on the empty lot adjacent to his house, that's safe.
I personally like the stuff. Its good for deep into shoulder season. It does put out a little more ash than others woods. I love the smell of fresh split Walnut. However its not in the same league as Black Locust in the BTU department....
BW doesn’t have a giant pith like you see in the newest picture, round at bottom of pic facing you, also evident in the piece to its right. Elms have pithes like that.