They were on a 2 track but within a mile of the road. It's unusual that they didn't follow the 2 track out. They passed houses on the way in, a mile and a half from there the truck was found stuck.
The arrow I drew points to the pipeline, that's the 2 track the truck got stuck on. Google wouldn't let me use that as the destination. You can see though that they could have walked North or South from the truck and would have ended up back at a road.
There was speculation that Jeff knew that area since he was a kid and knew that there were trails that led to Start City Rd. (Actually IIRC, someone said there is a 2 track that eventually becomes Star City Rd.)
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