Oaks are a diverse & promiscuous lot. There are hundreds of species native to the USA, and dozens have been introduced from else, and they naturalize. They will hybridize often. Collect winter twigs, and acorns, in addition to leaves, all 3 needed to make a good ID.
However, looks like one of the red oak - black oak swarm of species, culture for the group is pretty much the same. Note where it is growing, upland or wetland? That will also help with culture. Southern red oak is probably a good enough ID, until you find an oak expert familiar with your local species.