It is easy to get lost in here and end up doing all of the trails. There are several trails within this system but the maps I know of just call it "Waterfall Area". There are a few spots to park off of Old 6 Mile Road that allow entrance on the southern part of the trail.
This is mostly singletrack. Lots of climbs and quick descents leading to switchbacks. Seemed much harder than the 4-5miles that the GPS recorded. Some climbs are long and some of the surfaces are soft. Still a lot of fun.
Also there is a nice waterfall to view in the middle of it all.