I gotta go along with the majority and vote for Mulberry also....
not Mulberry looks like Locust when split has a stinky sox kinda smell almost like some crab apple trees have.
I have the same wood that I am burning. i have no idea what it is either but it is plentiful here in PA. VERY wet inside.....ok for heat, not the best, and somewhat stringy.
+2! Green mulberry. I've cut and split mountains of it. Many times the center is exactly like that as the tree or branch matures.YUP!!! The color and bark agree! Sounds like greenish Mulberry.