Were they all the same kind of tree?
The first looks like one of the smooth bark oaks.
In the second picture the split looks like a rougher bark oak and the piece laying on it looks like pine.
Fourth picture, bottom left piece, the bark looks like it is starting to 'shag' like a hickory, but I think oak does that as well but to a lesser extent.
The leaves on the ground are definitely oak leaves. Some are pointed lobed (red oak) and others are round lobed (white oak.) Might be some maple leaves too, but I can't tell from the picture. Do you have some pine on the property?
Oak is good for smoking, but pine is not. Hickory would be good too.