I would argue that Texas is it's own region, but I get it.
There is a large and active FB group of Texas Overland that has a lot of KMZ files of Texas routes stored in the "files" section of the FB page. I'm not sure if you're wanting to get them on board with you ( @Michael ) or not. I *think* the Texas Overland FB group owner/head is on here, but I can't remember what his username is.
Anyways, I'll chip in with Texas information once everything is live.