Originally Posted by TrojanHorse

Perfect! If you cross over the 91 and then turn left on Santa Ana Canyon Road you can ride over to Imperial. Head south on Imperial - it turns into Cannon after turning your legs into jelly. Then just turn left on Santiago Canyon Rd and juke around a little till you get to the regular Santiago Canyon Rd. For your water needs, there is a little subway/gas station/car wash at the southwest corner of Jamboree and Santiago Canyon Rd. I always stop there and top up before riding into the canyon. It's hot and dry even when it's cool.