No, for the GPS do not worry, but the truth, live that experience in the best way is without a cell phone, only the camera to save that magnificent adventure.
For the GPS it is good to download maps for offline mode and thus you have a security. At the entrance to the park they will give you a map. But eye! Look before the map where you have to go because sometimes the GPS can be wrong. From the General Grant in Kings Canyon, I wanted to go to Fresno, which is very easy, and the navigator has gone crazy and I went down a forest road closed by the storm and had to navigate with the map. A co-pilot comes well.
In parts not, but once you put the GPS but not at the signal the GPS takes you to your destination
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