Last Friday, there were 2 of these dead bugs in one of the urinals in the men's room at Fletcher's Cove along the C&O Canal. After I finished my business, I flushed, but the bugs remained. So I took out my camera and photographed them.
They appear to be some sort of stink bug (Pentatomidae).
Luckily, no one came in while I was stooping over the urinal with the camera against my face pointing inside. It would have been difficult to explain my motives.