Heavy rains will close the trails, and also it is only open Friday through Monday. There could also be flowing/standing water on the trails after heavy rains; typically found on Joe Johnston by the dinosaur tracks.
The Outer Loop route can be ridden in either direction. Although clockwise seems to be less challenging as you are going down more the rock shelves than climbing them. It begins on Joe Johnston at the Backcountry Trailhead.
Turning onto Far Reaches Trail, the rocks become a little less prevalent, but still provide for a technical ride. Towards the end of Far Reaches Trail, it becomes a nice, rolling singletrack that you can open up on as it transitions into Recharge Trail and the end of the ride.