Here is a random version of the route that I found on garmin. It looks like they zigzagged all over the beginning part. I think when I have done it in the past its ended up being about a 5 mile loop but there are little trails cut everywhere so you can make it long or short.
You can park in the left parking lot right where the car by its self is on this map The trail head is hard to see but it just up and to the left on where that car is.
You end up running kind of along US1. Mountain bikers have made tons of wood structures for them and I guess you can get all parkour if that's your thing.