Attempts to relocate it failed. So, as I was walking back to my bike, I decided to try and photograph one of many Green Darners floating above me and zipping about. Having no luck, I turned my camera on a dragonfly that had just landed a few feet away. I assumed it was something I had photographed before, so I fired away a few shots and continued on my business.
When I looked up the dragonfly later I tentatively thought it might be a Unicorn Clubtail. I posted the photo of it to Facebook for verification. Julie Craves was kind enough to respond w/ a polite 'No.' She wrote that it was a Flag-tailed Spinylegs (Dromogomphus spoliatus), and "that the only place in MI for FTSP is at Oakwoods Metropark, although they should probably be in other appropriate locations (see http://www.rrbo.org/pdf/sp
As for the rest of my evening it was pretty quiet. A fly-by Least Bittern was followed by a second bird that landed out in the Vermet Unit (from the Long Pond Unit). Dredge pumping was continuing in Cell 3, so there were no shorebirds about. I called it an early night, as it was hot and windy, and birds were not moving.