I have some great news regarding the Christmas Mountains of far-west Texas: legal access is now available through a waiver program via the Terlingua Ranch, which is located immediately northeast of the range.
Terlingua Ranch website: http://www.terlinguaranch.com/index.html. Click here to learn how to (a) get there and (b) go about getting a waiver/permit into the Christmas Range. They have reopened their operation including their cafe and cabins for rent. My wife and I stayed there back in 2005 and very much enjoyed our stay, and we highly recommend it. Given the remoteness of this peak, the Terlingua Ranch is a natural place to stay for a day or two, surrounding your now-legal hike. Sometimes they have local musicians perform. The Terlingua Ranch is set apart from the main community of Terlingua by about 35 miles, but it has that neat Big-Bend vibe nevertheless.
I have also updated my http://www.summitpost.org/christmas-mountains/155190 page on SP to reflect this new change in access.