Reason for this was to avoid the almost inpenetrateble "Monte Grande" . The large post oak and blackjack forest that bisects the state from deep south Texas almost to the Red River.
You mean the Cross Timbers? It runs clear up here. I used to live in it, now I live close to the eastern edge of it. The Cross Timbers is some beautiful country.
http://en.wikipedia.org/wiki/Cross_Timbers Pretty much the same thing! But here they are thick as all dickens.
They are thick up here, but are kept in check somewhat, by controlled burning and/or aerial spraying. I would make that map of the CT region much larger than it is. Certainly a lot of that country exists down around San Antone and northward much farther than the map shows. Up around the Emporia region there certainly are a lot of post oaks interspersed with native prairies. It exists on the western edge of my own county which isn't included in the map. My own immediate area resembles the area around Dallas and Sherman pretty much although there are rugged mountains between here and there that don't resemble either place they stand between.
