These are the nuts it produces.

With trunk like that maybe shag-bark hickory.

There appear to be multiple hickory identification keys on the web.

Here is a link that might be useful: Bing Search Results

This post was edited by bboy on Sun, Mar 23, 14 at 14:01

Thanks. That was helpful. I think you've narrowed it down for me to one of maybe three of those hickories.

As I remember it the only ones with the shaggy barks are shag-bark and to a lesser extent shell-bark hickories. Other than that details of leaves, buds and nuts are used to tell them apart - the keys will show what matters.

Definitely a water hickory. They usually have bark like a shag-bark (we have both here), but the seeds are exactly like in the picture, dark, wrinkled, and flattened, whereas shag-bark hickory nuts are rounded and tan. The leaves make the difference obvious too, when they eventually come out.