To add to my last post I just coincidentally saw an article saying Eagle Construction just purchased the land here (google maps, type 37.658828,-77.647569 in). That is off of the area I was just talking about. It looks like a dirt bike track of some sort. At first I was worried it may be someone's farm or yard, but now a developer owns it so I wouldn't be too worried with exploring it.
You can see the land they bought here as well http://www.richmondbizsense.com/imag...s-Farm.pdf.jpg
. It won't show you the trails cut in on that map though so you're better looking on google.