You can make this a loop or an out and back depending on how you do it. The fire road climb is not technical at all, but it definitely requires good aerobic condition. From the top, you can take the singletrack back down or the fire road all the way to Irvine Lake. The singletrack back down is very technical at some spots, especially after rain, so use caution. Also, jumps often appear around corners and throw new riders. It is best to ride these with an experienced rider first.
How to get there:
From the 91 freeway, exit at Lincoln and go South. Turn right on Ontario Ave. Turn left on Mangular. It curves left at the top, and Skyline is the first right turn. The ride starts here.
The best singletrack is about 5 miles from the bottom of the mountain.