Central Illinois Oak

I'm not an oak expert but the leaf looks like Southern Red Oak (Quercus falcata)

Thanks Dave; however, most sites say it only grows in southern Illinois, photo is from the center of the state.

some kind of burr oak???

I bet you @KentPfeiffer knows.

Looking at the acorns, I certainly see how you might think Bur oak, but Bur oak, being a member of the white oak group, will never have points on the leaves.

Regarding distribution, perhaps we can take into consideration the fact that oaks easily hybridize in the wild (although the white oak group will never cross with the red oak group). I am woefully inept with oak identification, however, other than those that grow in the Minnesota area.

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.

Yes, the acorns are what made me think of bur oak

the trunk

Hmn, not really what I was hoping to see. Looks more like Scarlet Oak (Quercus coccinea). Maybe....

http://www.hort.uconn.edu/plan...

http://plants.usda.gov/core/pr...

USDA's Plants Database indicates it only occurs in the southern part of Illinois, but Steve Packard has talked a lot about managing native woodlands in the Chicago area that contain Scarlet Oaks. They also occur in southern Wisconsin and appear to be scattered throughout Indiana so perhaps USDA's information for the distribution in Illinois is incomplete?

Flora of North America, and likely a better distribution database, shows differently for Quercus coccinea:

http://www.efloras.org/object_...