(Cobblestone, 54', 1984, pedestrian, 46-29-A) across Hidden Bridge Rd. NW of Pohick, Fairfax County, VA. Pohick Rd. (SR638 changes to SR641) NW about 2 miles from jct with US1 in Pohick to the bridge at the Cobblestone housing development. (05-2003, approx location) Photo by Don Burnell.