From their websitehttps://www.nps.gov/seki/learn/manageme ... licies.htm
Weapons and Firearms
Discharge of a firearm or weapon is prohibited within Sequoia and Kings Canyon National Parks. As of February 22, 2010, federal law allows people who can legally possess firearms under applicable federal, state, and local laws, to legally possess firearms in this park.
As of January 1, 2013, California law prohibits the open carry of any firearm within the parks. Persons otherwise permitted to possess firearms (in general) may possess a concealed firearm with a valid permit to carry a concealed firearm (CCW) from California. A CCW from another state does not apply.
Weapons (including, but not limited to, BB, Pellet and Paint Guns, Bow/Arrow, Slingshots, Bear Spray and other compressed gas irritant devices) are illegal to possess. Federal law also prohibits firearms in certain facilities in this park; those places are marked with signs at all public entrances. This also applies to concealed firearms with a valid CCW.
It is the responsibility of park visitors to understand and comply with all applicable state, local, and federal firearms laws before entering this park. As a starting point, please visit the State of California Penal Code web site (see Part 6 - Control of Deadly Weapons).