Hi Abel, I am from west texas, but lived in Austin for a very long time. If your heading to Austin, don't forget your digging tools as thats where the stuff is. Can't think of any place left there where surface hunting is any good. Digging sites are also now hard to come by as well, but there is pay dig at dripping springs (rio bravo)that has reasonable day rates. Good Luck!
Oh, there are plenty of places to hunt...more than you or I probably even know! Remember, the Native Americans have been here for over ten thousand years, while we (Europeans and others) have only been here for a few hundred. Lots of history to be found, no matter how many points have been unearthed to this point (hah, point)!