I have lived in California for a long time. I’m not quite at the point where I can say that I’ve lived here longer than I’ve lived anywhere else. I’ve lived in Hawaii for much longer (but I’m almost there).
If you live in California for awhile, you find Californians referring to things as “the” River or “the” 5. No matter what we are talking about, we refer to things as “the” one and “the” only. It shows up in our language, but then it’s backed up in our attitude and behavior. You can’t really escape it. If you’ve ever experience it before, you might be able to trace it back as “the” experience. It is part of “the” California identity.
identitySPECIALIST 
I’ve thought about this before. It’s part of our Californian self-centerdness. Even though Interstate 10 crosses numerous states, we refer to it as “The 10”. It’s ours, it belongs to us.
Unless of course you live in NorCal… There’s no “the.” In fact it’s an easy way to figure out who’s a native Nor Cal and who moved from SoCal! (speaking as a person who has lived in both but originally from neither)
That’s a great insight. I should have made that distinction and made it the Southern Californian “The.” Thank you for the insight.