From your description of the location it seems like it is a riparian loving species then?
I got a different impression from reading about it -- thinking it was drouth-tolerant open spaces tree. But that would explain why I did not come across it in the couple of years I worked with Texas A&M on the range land restoration project -- did not work near streams or rivers.
But reading about the spines (pic) on it I wonder if did not see one after all. On one birding junket in the desert I encountered a beautiful (and irritated) Loggerhead Shrike with a small shrew or field mouse that he had killed and impaled on a thorny tree -- they keep their food in a larder like that for later consumption (I paid not attention to the tree at the time!).
I expect finding smaller pieces for mandolin fret boards would be a better prospect?