The Statesman linked to a MySA historical photo thread from the early 1970s. Here's an aerial of some early development around Lake Travis. It took me a little while to find this development on Google maps because there has been so much development over the past 40+ years. But I did. Good luck searching for it.
http://www.mysanantonio.com/news/loc...#photo-8947930
Edit: This is what became Lago Vista.