Going North From Big Bend

I myself would be uneasy pulling a 39 foot fiver on 170, due to length and weight concerns. If you are interested in the scenery along 170, you could either drive out of Big Bend in your tow and drive the first ten miles or so of 170 past Lajitas; or, there is a fairly nice RV park in Lajitas (Maverick Ranch). You could spend some time there and explore 170 and Big Bend Ranch State Park, which begins at Lajitas.