Yes, Osage orange. I know it well. It is a fruit native to the United States. It is technically not considered native to California because it was not found there when Europeans first explored the continent, but there is conjecture as to how large a range it had when it was eaten (and its seeds dispersed) by now-long extinct giant ground sloths. The one you found certainly got there because a person planted it or one nearby.
Both the Osage orange and jackfruit are members of the Moraceae (mulberry) family, so that is good recognition on your part.
It is not edible. It is not poisonous and will not kill a person who eats it, but that does not mean it is edible. There are videos online of people eating it and not all of them hate it. I think that says more about their taste buds than the fruit's eating qualities. After all, Native Americans did not utilize Osage orange as a food source, which says something considering some of the other things they found ways to use. Last month, the All the Fruit YouTube channel released a video about the Osage orange (
https://youtu.be/21ye7d9inz4), and we talked about that very topic.