You've probably heard about Madeline Connelley getting lost near Glacier National Park in Montana for 7 days and 6 nights.

Here is an article from the Chicago Tribune:
http://www.chicagotribune.com/news/local/breaking/ct-rescued-montana-hiker-met-20170526-story.html

I think this is a pretty typical story. No gear because it was to be just a very quick hike on a trail. She got confused and headed in the wrong direction - most likely got off the trail.

Very luckily, the outcome was good.

I am a very big believer that the most basic handheld GPS can make all the difference IF the user remembers to set a waypoint for their car ... and the batteries are reasonably good (turning off/on to conserve power). I think a GPS with an electronic compass makes it more foolproof if not thinking so clearly.

A GPS with a hand held compass is even safer since its easier to turn off the GPS and still maintain a sense of direction, though following a straight line bearing is most likely impossible in such remote country.

A GPS, compass, and a PLB are the ultimate combo.

Of course you still need to survive long enough to self-rescue or be rescued.