I live 10 minutes from this site and drive past it very often.
I used to ride / off road my trucks here back in the day but it's nothing like it used to be. Theres a lot of people on Sundays, and theres alot of sh1t to watch running over or you'll blow out your tires. It does have some cool trails, hills, and lots of mud. Gotta watch whos there when you go, seems to be alot of shadey people from time to time.
The road it is on used to be called Hog Island Road, but ever since they have re-designed the airport runways, it has been changed and is now called Fort Mifflin Road.
The easiest way to find it is to come down I-95 and get off of the Enterprise Ave exit. Follow Enterprise straight for about a 1/4 mile to the first stop sign then turn left onto Fort Mifflin Road. The road goes winds around a bit, but no turn offs. The trails are around the first bend and all to the left side. You cant miss them. If you follow this road all the way down, you will pass the UPS building on the right side.
Having rode there in the past and seeing what it is today, I'd rather go somewhere else. Every once in a while they will find a dead body, or a burned up car down on the trails or in the water. It's not a bad area, it's just used as a dumping ground. And that water is nasty.... you dont want it touching you.
The city cleans the area up from time to time and as long as your not making fires or riding in the street, the cops wont bother you.
If anyone wants pictures, I will go there today and take some and post them on this thread for you.