Well... I don't like to dwell on awful stuff... but it's serious games we play in the hills, so sometimes it's good to have the discussion.
95% of my adventures are in Southern California. Most people think of our area as densely populated with hobos, hookers, rock stars, and tourists slathered in sun-block. That might be true, but there are rugged natural areas on all sides where the "civilized" people dare not venture. The pictures from earlier today were taken within two miles of a city and freeway. So in this case, the ride wasn't all that remote. Most of my rides are like that, only a few miles from civilization.
To the north of me is a range of mountains that tops 10,000 feet. To the east is a range that tops 11,000 feet. And to the south is a range only half as tall, but if you are not prepared, things can become serious. Every year you read about someone in SoCal dying of thirst... or freezing to death... or falling to their deaths. And sometimes bodies aren't found for quite some time. Like I said, it's serious business.
While the above is all true, it doesn't completely answer the implied question. Riding in the wilderness is safer than walking down the street in the ghetto. Carry plenty of water, an emergency bivy sack when it's cold, a little nutrition, tire plugs, a tube, and a flashlight. Tell someone your intended route. Study the maps before you go. Risks CAN be mitigated.
Rattlesnakes are not the threat that people imagine. They don't like people. They don't want anything to do with people. Give them half a chance, and they'll slither away. They feel your footsteps and hide before you know they're there. It's the same with mountain lions, bears, coyotes, and surly jackrabbits. None of them want anything to do with us.
So there you have it, the God's honest truth. Renew your passports, book the flight, pack up the wife and kids, and get ready to spend your vacation dollars exploring the SAFE Southern California.