It can be very difficult to find anything in open desert, it’s not like a regular neighborhood where you have street signs & land marks.
In the remote areas, there is literally nothing for orientation. I don’t know enough about GPS to say if that would be accurate, I would imagine it depends on how accurate the mapping software was.
http://www.azcentral.com/12news/news/articles/2010/04/30/20100430pinal-county-officer-shooting.html
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Even the cheapest of GPS units you can buy at Sprawl-Mart allow for 3 meter solutions.