I was thinking Copperhead as well when I first looked at it, but I knew that as I scrolled through the pics, I would see one of the green tail. Make sure you get a tail shot of the next moccasin you see, as I have never seen a baby, and have only heard of the green tails.
There has only been one sighting of a Copperhead on my property as well, and it was by Sean while he was driving to my house. He stopped in the road, because it was crossing the street at dusk, asnd we couldn't find it again after he got me. I'll keep looking.
Grats on the new sighting at the PRWMA.