The firefly family of beetles, Lampyridae, does indeed live here, with nineteen different species according to one source.
We don't have actual, light-emitting fireflies in California, although it seems that some of the larval forms do glow when disturbed. Not very practical, running around in the woods at night hoping to disturb a tiny insect so you might see it glow....
It seems that our fireflies generally don't go out at night. One species, Ellychnia californica, is diurnal, like, "dude, where's the beach?" (they do live in coastal areas, but probably aren't beachgoers). Sun-loving. Not much point in glowing if you spend your days hanging out on goldenrod flowers.
The closest species to Sacramento is probably Pyropyga nigricans. These guys look a lot like Ellychnia, mostly black with some orange-red markings on the head.
Perhaps because our fireflies don't glow, there doesn't seem to be a lot of information about them. I can't find out what they eat with any degree of certainty, either the larvae or the adults. They seem to like places with at least seasonal moisture, and live at the borders of meadows and forsts.
Most species records are from Santa Barbara... and Tulare counties. San Luis Obispo has its fair share, too. It's funny that the same species can occur inland and on the coast, but not in between - maybe it's just that nobody's studying them in other areas.
Tulare... hmm. Might be an excuse to go hike around Seqoia National Park with a macro lens. It would be nice to have shot of a real California lampyrid and an adventure story to go with it!
This is what our fireflies in California look like, more or less. Not the ideal creature for a logo, even if they might be beneficial and part of the native ecosystem. Glowing isn't everything, after all.