Been meaning for months to post this. I worked up a 4 day, 1000 mile county road loop between Lubbock & Fort Worth. It's about 85% dirt and 15% pavement. I have ridden it twice with a few changes the second time...first time solo and second time with a friend both of us on KLR 650's. The first half is a different route than the second so you're not repeating your ride. The scenery varies widely from wild breaks off the caprock to hilly & wooded closer to Fort Worth to Abilene. The ride is not particularly difficult with a mix of graded roads, some rutted depending on recent rains, and shallow sand in some areas. Speed average is 45-50 mph, more or less per terrain.
The loop could be started at any point and with a little planning motels are avaiiable along the route.
If anyone's interested in trying it I have gps routes in Mapsource that I'd be happy to email you. I also have it mapped out on Roads of Texas Mapbook.
Let me know if your interested. Jerry Lewis 806-632-6560