A herd of sheep (5 or 6 strong) was sitting relaxed on the east side of the tunnel. A place I've seen sheep many times it is great for spotting, but bad for stopping. There is no safe pull-in, no spot to top and watch.
A male sheep walked down the hill, over the tunnel, and down to the herd. I saw the approach, the herd's male lower his head (in a seemingly unfriendly "welcome") but I had to drive on before I could see what ensued. I assume it wasn't a friendly encounter.
There are parking spots the other side of this tunnel, and the nearby tunnel 2, so it ought be possible to hike to spot to find/photograph these guy.