Federal law now allows visitors to carry guns in national parks, but you can’t just slip a loaded pistol into your backpack and take a hike. Pay attention, because this is a little complicated. You will need a concealed weapons permit to carry the loaded gun in the backpack. But you don’t need any kind of permit if you just want to stash your loaded weapon in the tent.
http://www.fresnobee.com/2010/03/22/1868629/fed-state-rules-blur-issue-of.html