I hear them yipping and squealing like that all the time. No particular time of year. And they're moving.
When I'm hiking and camping, I try to camp up on the hillside, as far up as I can get. Besides just liking to be high up, I figure that the coyotes are more likely to be traveling around down in the bottoms more so than up on the side of the hill. And they do. A few times I have heard them making racket as they pass along the creek bed way down below me.
