I have to say "that's amazing" to anyone who is proficient at mountain riding. I love ridiing a bike but in Los Angeles, it can be difficult. I've seen people riding up Laurel Canyon but is just so dangerous... it's really not worth the risk. If you have the car to carry your bike you can head up to the nearby mountains and make it happen, but for those of us who don't, we only have to watch in awe.
Nice work, bicyclers. Any tips on how to get started on regular land? One of these days I hope to live in an area part time where it's possible to head up a hill without getting squished... physically or by a car!
You may have some nice trails right within reach for you. It's been years since I have been out there so I don't know for sure. When I lived in Austin, Texas we had some that were hidden away right in town in parks.
Here is a page for you to check out some trails...