California is ruled by osteomancers -- wizards who dig up fossil bones and devour their essence. The La Brea Tar Pits were the original California mana-rush, but there's extinct (and non-extinct) magical species all over the world.
(The book does not address how humanity could evolve in a world with krakens and cerberuses and so on, and still wind up with a California that had a Walt Disney in it. This is because it's unaddressable, of course.)
The protagonist is the son of a powerful magician who was killed by the Hierarch of Southern California. If eating the bones of a magical animal is good, see, then eating the bones of a magician is better. The Hierarch is the top of the food chain. It makes for a really vivid setting, rather Deviant's Palace -- yes, I can compare anything to Tim Powers -- but somewhat stomach-churning in the details. It's an autocracy of greed-mad cannibal monsters, unpleasant through and through. Putting a good-guy osteomancer-thief through amusing hijinks isn't quite enough of a distraction.
I always like convincing magic in my fantasy, and this is convincing, all right. Osteomancers operate by smell, above any other sense; that's not an angle I run into often. (A TV mini-series would be a challenge.) The characters are appropriately motley and the plot is appropriately twisty. Agendas everywhere. I just don't really want to go back.