I found this moth in the BYG just after arriving at FWG this morning. It is often associated with black locust trees and we certainly have plenty of those in the ravine, so I'm surprised we don't see this moth more often. It is quite small, a member of the Geometridae, and wary. I tried several times to get close enough for a macro but it kept flying away and I had to be content with this severely cropped image... hence the lack of clarity.