Thanks to Zen Slug for sharing the map below.
If you remember at the end of the ride when we hit Angeles Forest Highway, there's a little parking lot across. That's the trail head and on the map above, it's the spot with a lot of red markers with the name Aliso Spring. The trail is highlighted in green (continuation of the SCD and Mt. Gleason), and it's not as long as the one we did last week but pretty challenging for riders like me.