KoolHandLuke said:
As mentioned above, 277 would be a solid East -West Boundary that would end up with Northern boundary in San Angelo, and then making a line straight over to Midland/Odessa and on to NM. I'm pretty sure most folks would accept that. But then again you always have the people who argue that Lubbock is West Texas, and it damn sure isn't. Of course I'm from West of The Pecos, so I think anything on the other side of the river is questionable.
This is the correct answer.