This happens more frequently than you might think. GPS is notoriously inaccurate in some mountain areas and in large uninhabited areas of the West. Just about every winter we lose some poor soul who followed his gps out into the wilds of Wyoming up a two-track and perishes after becoming stuck.
A friend come out from Kali a couple of years back to ride along on a pronghorn hunt in the Red Desert area of Wyoming. I knew exactly where I was going and we compared it to his gps, which was at one time over 30 miles off and would try to run us down through cutbank gullies or over steep enbankments. They may be just fine for down in the city somewhere but I would never completely trust one out in the puckerbrush.

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