Tesla's Current Supercharger Map
"The Texas Triangle is #Supercharged! Model S owners now #drivefree between Houston, Dallas, Austin, and San Antonio."
Current List of Superchargers in Texas
Remarks Tesla Motors via its Facebook page.
That triangle includes stations in Columbus, Corsicana, Huntsville, San Marcos and Waco, Texas.
Tesla will eventually add a couple additional Superchargers in Texas, but for the next year or so, those 5 stations are likely all Texas will get.
As Tesla states, the 5 stations in Texas connect drivers in Austin, Houston, Dallas and San Antonio.