The 12% grade occured along Broadway Terrace. But I can't remember where exactly?

Are you referring to the ride on the 18th or the 25th?

The 18th - best advice is to be cautious on redwood which is somewhat narrow and a steep descent in my opinion.

The 25th - Wildcat canyon can be a ***** to climb - especially in the beginning. But if you can do the three bears (and certainly Diablo) you can handle Wildcat.

From Snake and Skyline - go down skyline, turn left on redwood, left on pinehurst, then take pinehurst back to skyline (turning right on skyline to get back to snake).