if you look at happycow.net, you will see there are 2 natural food stores and what looks like a raw vegan farm that hosts lunches twice a week. Not the best news but the natural food stores could be helpful for you.
Of course remember, just because there aren't veg restaurants there, other restaurants will most likely have some options.
The Gazpacho restaurant has a small vegetarian section on their menu http://www.gazpachorestaurant.com/ (remember to ask for no sour cream/no cheese at mexican/tex-mex restaurants)
East by Southwest is a Japanese type place and has a section on their menu for vegetarian sushi as well as a couple stir fries http://eastbysouthwest.com/menus.html (remember to ask for no egg in the stir fries)