TFS scrubbed all the documents with frequency lists and maps from their web site a few years ago.
The latest info from 2013 and 2014 with the zone boundaries is in the database and the wiki article.
Texas A and M Forest Service Scanner Frequencies and Radio Frequency Reference
Texas A and M Forest Service (TX) - The RadioReference Wiki
I couldn't find anything later than that. I don't know if anything else has changed. I don't have a current map.
In the past couple weeks TFS air and gound units responded to a couple fires around here and used 122.925 which I assume is still primary air-to-air for the whole state.