I think many of us SoCal locals blow right past the Cleveland National Forest on our way to places that are...well... more exotic. Being right in our backyard, I always thought of it as boring. But like the other maps when you spend a lot of study time, you'll wonder how you will ever get to see all the stuff that is there.
Cleveland is more cruising territory, but there is an awful lot of it. Not much crawling, but tons of open trails to raise some serious dust on. For incredible views of southern california, Cleveland gets you to 5,600' Santiago Peak with many miles in between. In the winter you can get from the beach to Cleveland's sometimes-snowy tops in about half an hour. And you won't run across a lot of other people in Cleveland's 300-plus square miles:
Download the Cleveland national Forest file here