We were heading west out of Utah on an early morning run trying to get an early start to avoid the heat of the day.  Because of the early morning departure we were both sleepy and forgot to turn on our garmin nuvi sat nav.  As the sun finally started to come up I looked at the car compass and saw that it was not working properly.  Then I turned on the gps and discovered that somewhere in the dark we had made a wrong turn and were now miles out of the way and would have been lost without our sat nav.