Google Maps once directed me and my family up a logging road in Washington state which became fainter and fainter and finally ended in a dead-end clearing. There had once been a further road (maybe connecting to someplace) but it was now blocked with boulders, and closed for so long that trees were growing in the middle of it. By this point all GPS and cell reception had cut out.
I was lucky that my sense of direction is good enough that we could backtrack out again.