It looks like some of the cliffs either just downstream from the overlooks or in Mather Gorge. Do you remember about where on you were? Was it from the Rocky Islands themselves or from the Billy Goat Trail? That might help me. It's definitely not at Dihedrals or Juliet's Balcony.
Norfolk's a dump, in my opinion, though the D.C. area isn't exactly the Garden of Eden. However, Great Falls is a spectacular little slice of nature and good for an escape. If you ever do set foot out here, don't miss it!