Photos of White Hill Open Space Preserve Hiking Trails

Can someone explain that following the route alltrails maps out that you seem to end up at a point on the fire road after you come down white hill mountain that has a sign across the blue ridge fire road stating no trespassing? There seems to be a single track off to the right that wants you go down instead. As I was running this trail I stopped and turned around with my dogs,

Any help appreciated.