I have done some recon in the area. Looks to be a tricky penetration.
There are two potential roadways in. Old Portland road turns right and leads back to a juvenile detention facility (New Beginnings Youth Development Center) that serves youth from DC.
Unfortunately there is a guardhouse right at the turn (see red mark on attachment). Strongly worded agreement to search of all property.
You can also notice that the actual grounds (circled in green) can be accessed via the woodland job corps center. However, they have clearly marked No Tresspassing signs and a less imposing/unmanned guard house.
So...that leaves running through the woods from Old Portland road. Might be possible as a hike in from some distance away.
