I've been to the Hocking Hills, several times, to see the different native orchids that can be found there. My last trip there was 2004, so it has been a while. There are at least 11 species of native orchids in the Hocking Hills state park. To see them all you have to visit in May, then June, July, August and September. And I have. The rarest I've seen was a species of Isotria. Most abundant were the Cypripedium acaule.
Cypripedium acaule - click to expand thumbnails.
Galearis spectabilis - a lovely pink & white thing.
Most books list this as quite rare, Isotria, but in truth it might be that it is just difficult to spot. You can be standing on top of it and the green and brown flower is invisible against the leaf litter. Had to hold a cloth drape behind it to even see it in a photo. Without the cloth, it is invisible. So it might be more common, but most just walk past it. Without our host acting as guide I would have never seen this orchid.
Tipularia discolor - another orchid that is not very showy and not easy to spot. Not in bloom, it has a curious red-brown leaf, it flowers after the leaf dries up.
Hobart's Cave - one of the more recognizable HH landmarks.