Young shagbark hickories and an old silver maple
These two young shagbark hickories are growing in a road ditch. To be completely honest, I call all shaggy-barked hickories "shagbarks", but some of them could be shellbarks. I don't have a clue how to tell the difference between shagbark and shellbark hickories from the bark. There are some minor differences in their leaves and nuts -- enough to make them two separate members of the walnut family.
Here is another shaggy-barked tree -- an aged silver maple. Old silver maples develop long scales of bark that are loose at the ends. This sort of bark on any species of tree is called "exfoliating."
It would be difficult to confuse a shaggy-barked silver maple with a shaggy-barked hickory, though, even in winter when no leaves are present. Silver maple trees have a broad, spreading crown with the central trunk breaking into massive branches. The crown's width may even be more than the tree's height! Shagbark/shellbark hickories generally have a much narrower crown, about half as wide as they are tall, and their strong central trunk persists high into the tree.