SS's up:
http://img34.imageshack.us/img34/5373/screenshot3qf.png
http://img530.imageshack.us/img530/8467/screenshot0s.png
http://img301.imageshack.us/img301/8485/screenshot1ak.png
http://img576.imageshack.us/img576/7909/screenshot2yp.png
Kind of creepy/obsessive, actually.
I'm guessing we'll get some DLC about him!
I've just visited the place, thanks for noticing. What is the Divide actually? I remember Johnson Nash saying "I hope a storm from the Devide skins him alive." or something to that effect while talking about the courier that passed his job to you. I didn't really understand it then, but that 'graffiti' in Canyon Wreckage also simple says "the Devide". Note it's written with a capital "D", so it could be a place or region. My wild guess would be "the Devide" is a DLC area located on the west part on the map, the area that's currently blocked off by mountains. The Canyon Wreckage appears to be the way to get there, if the trash in Canyon Wreckage is cleared. That would probably be where the other courier is located.
Also, I don't know if you agree with me, but the signs saying "Courier 6?" and such appear to be a direct message to you, while "the Devide" is more written like it's telling you what's ahead. A little like the signs saying "Hoover Dam" to the east of Boulder City. "You can go home Courier" looks to me like maybe "the Devide" is home? Not sure about that of course, but it's kind of a weird message if the Devide isn't the Courier's home. "Lonesome Road" doesn't make much sense to me. Well yeah, maybe you're supposed to go there alone, like in for example The Pitt and Point Lookout, but it's hardly necessary to put that up as a sign.
Well, all heavy speculating of course, but the presence of Canyon Wreckage is definitely hiding something.
Edit: Also note the suitcase under the writing that says "Lonesome road". Time to travel, baby!