I've lived in the Mountains of Northern California for most of my life, with 4wd and AT tires I've never actually needed them. I just carry a cheap set I found in the garage which don't even fit my tires for going through checkpoints, to verify I have chains on board. I've never actually had to show them to anyone.
For the people laughing about us Californians worrying about this stuff, believe me, some parts of California (like where I live) get a LOT of snow. In the first pic of my old house, so many trees were down we lost power for a week.
This pic was from Feb 2019, a few miles from my place (admittedly a few thousand feet higher as well).