OBSERVED: After midnight, I heard more than a minute (possibly 2), a horrible, extremely loud screaming, unlike anything I've heard before or since.
I was in a cabin getting ready for bed, but wide awake. The scream was very loud and seemed to be less than 30 meters from where I was. The sound was not a cat screaming, was not human, not bear. As I was hearing it, I ran through my mind the different animals, what it could possibly be. But it was a large animal, the volume was so loud. And a high-pitched screaming.
I joke with people to whom I tell the story that it sounded like wildcats being fed through a meat grinder, but that only captures the high-pitched loudness and intensity, but it was NOT a cat. I didn't know what to think of it. I had heard of Bigfoot, but didn't know that they had been heard screaming. But 6 months later, I read an account that referred to this horrible screaming, and I knew that was what I had heard.