Hi Will, ENTS,
it isn't the same place, but i sampled pignut hickory and post oak growing on Bear Island and the Billy Goat Trail on the northern side of the river across from Great Falls St. Park - http://tinyurl.com/3ae7eob
though not impressive in stature, the oak and hickory are about 90 to 175 years old this yr [sampled in 2003]. the hickory are, on average, a bit older than the post oak.
and, because they are mostly growing on rock, they are wickedly drought stressed.
unfortunately i do not have any digital pictures of these trees. if you zoom in on Google Earth, you can pretty much see each tree.