I agree with Eric, it looks like sassafras to me as well. The outer bark looks exactly like sassafras. The reddish inner bark too. The end cut as well, see how the early wood fuzzed up like that? Yep, sassafras does that more than most. How does it smell when cut or sanded into dust. Sassafras will give off that spicy smell.... unless it's dry or old wood that has begun to decay, then it can be hard to pick up the smell.
One thing that makes me suspect though.... freshly cut or split sassafras will show a clear difference between the sapwood and heartwood... with the sapwood being white, and less than an inch thick.... a lot like osage, mulberry, locust, in that regard.
How old is this wood? It looks kind of grey-ish and washed out for sassafras. But maybe that's just how it looks in the picture. Was it recently cut from a live tree? Or has it been dead for a while? If so, standing? Or down on the ground?
I peeled the bark off of a bunch of small sassafras logs today that will be used in the smoker.
I also have a few big sassafras staves with the bark still on. If it'll help, I could dig one out and post a picture of it here.