I really wanna know...Is the divide the calafornia river?What is it?

Grand Canyon. http://fallout.wikia.com/wiki/The_Divide

There it is. The Grand Canyon is also the headquarters of the Legion so if we happen to get DLC set in the divide, it may be more Legion based.

Actually, http://fallout.wikia.com/wiki/Flagstaff, Arizona is the capitol of Caesar's Legion, the Grand Canyon is part of their territory.

Well if it's a sizable DLC like Point Lookout it might include Flagstaff if it's near to the Grand Canyon.

Oh.Thats where Joshua Graham was thrown off.Might see a dlc there and at that place with something saying Go home courior 6

Well, the divide isn't necessarily the Grand Canyon. That's what most people believe it is. However, "the divide" is graffiti'ed onto a heap of trash blocking a passage to the west, towards California. And Johnson Nash's reference to it makes me think that it may have to do with your "history" with would-be Courier 6 (if it ends up being a DLC).

I have to agree with follower I think its the western part of the map that's blocked off. Not the grand canyon.