In Northern Virginia, the MUPs/trails are under the control of environmental services or state park authorities.

http://www.nvrpa.org/trailrules.html

I am not as familiar with Maryland's trails and associated rules, but I believe that you are correct Galen. Although Maryland, Virginia, and DC all publish maps and guides that refer to the regions trails--such at the WOD and CCT--as bike commuter routes.