Ernie M. sent me a link via email that is of interest for those who are researching the Baca family. Somos Primos publishes an online journal. In its 141th online issue, there is an article titled Origin of The Cabeza de Baca Family in Spain by Dr. Eric Beerman, Madrid. The article is about half-way down the page.
I have done research on the Baca family, and I agree with the history that he wrote in this article.
Click on this LINK to view the article.