It's difficult to say without seeing more, such as underneath of leaves and fruits. The photo showing leaves looks to have some small fruits or nuts so if you can take a closer look you might have a better idea.
Quercus hemisphaerica looks similar with the young bark being mottled, the rest of the descriptions might help.
http://www.duke.edu/~cwcook/tr...
http://dendro.cnre.vt.edu/dend...
Multiple trunks may have been caused by the main shoot being broken when young, there could even be two trees growing together.
They set around making thickets, and are fast growing.
http://www.floridata.com/ref/q...
