Screaming or howling in Skamania County, Washington

My wife and I were on a family camp out with my inlaws. I stayed up after everyone had gone to bed to let the camp fire burn down. I had noticed earlier that day the dogs would go nuts barking into the woods. Since there were no other campers within miles of us I figured it was deer or some other critter they were barking at. It was after midnight and was quite dark the fire was down to coals. I got this intense feeling that I was not alone, I put it down as over active imagination that feeling you get when you are alone but feel like someone is watching you, so I decided to head for the tent. Some time in the morning between 3:00am and 4:00am I was awakened by what I thought was coyotes howling. It was high pitched. It was not loud at first but grew in intensity, it awakened my wife also, it sounded like one than others joining in. It sounded like five or six animals as it grew in intensity. I knew it was not anything I had heard before. I jumped up thinking it was an alarm and that the woods were on fire but the night was dark and no smoke so we listened to it and could tell it was some sort of animals. I thought it was elk my wife and sister inlaw had spotted a heard down the road earlier that day but I have never heard elk sound like this and if it was they were in pain, as I said it started out low and others joined in and it grew in intensity like it was far away and getting closer it lasted about 10 maybe 15 seconds and then just stop abruptly! It was in unison starting with one than another until it sounded like 5 or 6 going at the same time and then just stopped all at once. It was a very high pitched scream, not a trumpet like an elk or the squeek of a deer and it was not the cry of a cougar. I have heard these animals before and this was new to me. When we were on our way home after the camp out we stopped at the Eagles Cliff store and my wife mentioned what we heard to the girl working there and she said there had been other people that had heard it too and some mentioned having rocks thrown at them out of the dark. I dont know if what I heard was bigfoot. I never believed in the story. All I can say is it was something I had never heard before.