Quercus lyrata or Quercus macrocarpa maybe? Their ranges don't overlap much in Texas so the location of the tree will help. Also, if I had to put money on that fine specimen, it'd be macrocarpa

This post was edited by j0nd03 on Thu, Jan 16, 14 at 20:48

The branching looks a little erratic and the leaves superficially look like Q. lyrata but Q. macrocarpa sometimes hybridizes with Q. stellata so...more shots of leaf samples would be helpful.

By the points on the leaf tips it appears to be a species in the red oak group. This would eliminate Q. macrocarpa, lyrata and stellata. Based on the leaf shape and gray bark I say a variety of Southen red oak Q. falcata.

I zoomed in on the picture and don't see any bristles (before I posted the first time) so I am nearly certain it is a white oak relative

Is it me or are the twigs "corky" in some places like Macrocarpa would be? Yes, I think leaves look like Lyrata also, though.

Check out Quercus x guadalupensis.