Right before the Texas Academy of Sciences meeting, I ran into legendary Texas botanist, Bill Carr! He was doing a little survey for the Tobusch fishhook cactus (Sclerocactus brevihamatus subsp. tobuschii) around Kimble County. He told me of this location, and I was lucky enough to find a few individuals! Location greatly obscured due to conservation concerns:
http://tpwd.texas.gov/huntwild/wild/species/tobusch/