Going by the acorns, I would guess Black Oak (Quercus velutina)
http://www.plantsystematics.or...
Black Oak (Quercus velutina)
But, oaks can be really hard to ID with any certainty. In some respects, the red oak group is almost more of a big hybrid swarm than a set of distinct species.
Do you have any pictures that show the lower part of the trunk? That might help (or not) with the ID.
