The Transportation Security Administration found the gun Wednesday night.
The passenger, Fred Black, was ticketed for travel from Salt Lake City to Ontario, California.
The TSA found a loaded 22 Magnum Mini in his carry-on bag.
Black has been charged with carrying a concealed weapon.
In all of 2012, the TSA discovered 20 firearms at the security checkpoint.
TSA CLARIFIES GUN LAWS IN AIRPORTS:
Firearms, ammunition, firearm parts and realistic replicas of firearms are always prohibited in carry-on baggage. However, these items can be transported in checked baggage provided the traveler declares them to the airline during the ticket counter check-in process, a TSA statement reads.
It continues, Firearms in checked baggage must be unloaded, stored in a locked, hard-sided container. TSA urges passengers to contact their airline for specific firearm and ammunition policies and to check local laws related to the carrying and transportation of firearms.