Hello,
I would try looking into the C. L. Sonnichsen Special Collections Department at the University of Texas at El Paso. Here is a link to their finding aids; however, they have so many collections that are backlogged and are not listed.
I would also ask Claudia Rivers (Email: crivers@utep.edu; Phone no.: (915) 747-6725), who is the Head of the Special Collections and Laura Hollingsed (Email: lholling@utep.edu; Phone no.: (915) 747-6726), who is the Manuscripts Librarian and Archivist if they can help in any way. They are wonderful, knowledgeable, intelligent women; and are always so very helpful.
You can also try the El Paso Times Archives at http://www.elpasotimes.com/archivesearch
As well as the list of other archives and valuable resources at http://www.epcounty.com/history/border_archives.htm
Good Luck!