Stayed at Wayah Shelter last night. It was 8 PM, I was alone and was just about to fall asleep when I heard a single howl coming from the North at a distance of maybe 1/4 mile. It was quickly followed by a second howl and then several more in quick succession. Not a minute later they were in a frenzy and could be heard viciously attacking something. I could heard yelps, growls, and all the sounds you would expect to hear on an episode of When Wild Animals Attack. The frenzy lasted for a minute or two, things got quiet for a few minutes, then it started again for another minute or so.
Here I am laying in an open shelter with a pack of hungry coyotes nearby and all I have are a couple of trekking poles and a little pocket knife to defend myself. I peered into the darkness for the next hour, listening for the faintest sound that would tell me that they were getting near. I finally heard a single howl coming from the NE and from a little further distance. They were moving away - walking upwind in search of their next meal.
I slept with one eye open and didn't hear anymore howls during the night. I'm not sure what I would have done if they had come into the shelter area. I've read a lot of advice on how to handle encounters with bears, but not so much on what to do during an encounter with coyotes.