I saw this at Lowden-Miller State Forest near Oregon, IL. There were many of them, and they seemed to be attracted to horse feces. I looked up the Common Spring Moth and the Rare Spring Moth and they both looked very similar to this species in structure and overall pattern, but not quite right. I observed them on a few different occasions. They seemed to be most common in early June and became scarce by July. Are there any closely-related species that it could be?