I have been taking a couple runs up to Santiago peak on my dual sport the last couple months. The trips have been really great. It is a really quick getaway for us OC folks and it feels like you are totally away from the city. This last run, my buddy and I rode to the radio towers at the peak, and down the backside to Tom's Farms. I highly recommend taking a run up if you get a chance. It is an easy trail and gets your offroad fix in without having to drive too far.
My plan is to do the Main Divide soon in the 80 down to Highway 74. Seems like a nice Saturday morning run