Only on the roads, paved or dirt. No off road travel is allowed. There's plenty to explore. However, the longest of the dirt roads, the River Road, has been affected by the recent flooding. Not sure what condition it will be in by Thanksgiving.
Link to the Park's road info:
http://www.nps.gov/bibe/planyourvisit/take_a_drive.htmOne other road that's not listed there is the North Rosillos road, which runs west from the main road just south of the Persimmon Gap entrance. It exits the park and will take you to Terlingua Ranch; but there's lots of branches, etc. so talk to the Rangers and get a good map if you head out there.
