That, my friend, looks like mulberry to me.......smells wonderful when burning, puts out decent heat, but man does it like to snap, crackle and POP when burning!
I'm going to go with mulberry now also. Here is a fresh split reference pic. Osage "left" mulberry "right".
Mulberry for sure......................once it seasons for a few weeks, it'll turn a more golden in color...................I've got about 3/4 cord somewhere in my stacks that I'll be getting into this burning season.
My first thought was black locust, since it is also that yellow color. However, I don't think locust has the white sapwood. It's yellowish-green through and through. Also have no experience with mulberry anyway. Second wood looks like white pine with no bark. The knots and color in the first photo, and the tailgate photo, give it away.
Some of the mulberry I CSSed a while ago.................see the same yellow inner and the while outer.
When it's fresh cut, it's splits surprisingly easy also!!! Looking forward to the burning experience with it...............this year will be the first. Mulberry is one of the "better/primo" woods you can get from what I read here.