Tonkawa is a language isolate formerly spoken in Texas, particularly Central Texas, where I live. However, the American government forced the Tonkawa people out of Texas and into Oklahoma. There are no native speakers of their language remaining (sorry if this thread is in the wrong forum), but there seems to be a revival movement.
Recently, I was pleasantly surprised to find this language booklet for beginners learning Tonkawa:
http://www.tonkawatribe.com/Languange%20booklet.pdf
With audio accompanying it!!
http://www.tonkawatribe.com/Lesson%20One.mp3
I didn't think I'd ever hear a recording of Tonkawa so easily!