Yes there is. I only did it once, back in 2002 with the Warrior's Society.
We started from the Ranger's Station down below and climbed up Old Hwy 38 to the General Store at Angelus Oaks. Took SART (to the left, away from where most people go) to a fire road that eventually climbed up to Morton Peak. Took a singletrack down. The fun part was trying to get back down to Hwy 38. A lot of guessing on a dirt road. An epic ride.
Up the fire road:
I believe this is where the traihead for the singletrack down is located:
Pics of the singletrack that goes down from Morton Peak:
"I hope your gravity droppers all seize up....BASTIDS." - Aquaholic