I usually don't get into these wood ID posts, as they usually devolve into arguments and we never find out the real answer. Leaves are the best way to identify wood. On these pieces, the bark says elm, maybe walnut, definitely not any hickory I've seen in WI. The inside says walnut to me, the heart wood is a tad darker than our red elm.
That said, let it season a year or so, then hit it with a draw knife. You'll figure out in less than a half a second if it's elm or walnut. Walnut will work like warm butter, the elm will laugh in your face.
Kyle