Unmarked paths/trails.
From the Washington, D.C. area take I-270 north toward Rockville and exit at Route 28 west toward Frederick County. Approximately one mile after crossing the Frederick County line you will see the main parking area marked before reaching the Monocacy River Bridge. For additional access points, contact Seneca Creek State Park, which manages this facility.
http://www.tripleblaze.com/trail.php?c=3&i=4230