Screaming or howling in Kittitas County, Washington

I live in Cle Elum Wa. During the winter of 96-97, which is the winter we in the Upper County had an accumulative 17+ ft. of snowfall, my little herd of seven horses was boarded on a mountainside pasture 7 miles east of our house, at a place along and above the Yakima River. It was in the middle of winter, maybe January, that I heard something, and it was like nothing I have ever heard before. To feed the horses, we had to drive up a long, somewhat winding driveway. But, with the snowfall, we couldn't get my truck up that steep drive, so we ended up going out late each night with two bales of hay in the back of my SO's Subaru. We had to drag those bales up on foot, from the road. It was tiring work, because of the deepness of the snow and the steep incline of the drive. We'd had to dig a little spot through the plowed snowbanks to park the car just in case someone came along the road, as it was not really wide enough for cars to pass. (It was so deep that one horse walked out over on top of the barbed wire fence, without a scratch on him.) My BF (boyfriend, not BigFoot) worked late, and would not get home til 10 or 11, and we'd go out to feed most nights around midnight or shortly thereafter. After feeding the horses in the open corral behind the barn, I would sometimes walk out into the darkness beyond the barn, and howl to see if the coyotes in the area would answer me, which they often did. (The house was fairly isolated along this canyon road. I wouldn't have done this if there was a possibility of getting shot by a neighbor.) One night, after directing my call to the east, where the coyotes usually were, something very big answered with a howl of its own from the hillside behind me. It had amazing lung power...it was extremely loud! It scared me a bit, as I did not know what the animal could be...it was most definitely no dog nor coyote nor wolf. I only had a weak flashlight with me, and I couldn't see what it was that made that call. I was not going to go up and find out what was up there. The only other person who was there was my SO, George. He jokingly said it was just someone's rottweiler, but I told him that was no dog. There was a summer cabin further up the mountain on the one road that goes up on top, but that road is not kept clear by the county, and there were no snowmobile tracks up there during this time from the highway. What is up in that general vicinity of where the howler was, are a couple of year round springs, and we had salt/mineral blocks up there during good weather. (Also, I have a small flock of chickens, and when they passed on, I would bury them in warmer weather but in the winter, would take their bodies out near the tree line for the coyotes. We had a stray dog come in and dig her way into my chicken yard and house and butcher quite a few of them.) One of my Appy geldings was acting very strangely quite often...he would always bring up the rear of the herd when I would call them in, and he often acted like he was on alert for something. I could never figure out why that was, but he would not want to go in to the corral to eat with the others. I would almost have to drag him in there. He would keep looking out towards the dark, out towards the trees, and would be very nervous. I would walk out in that direction, shining the biggest flashlight we had, but could never see anything that would make him act so spooky. Coyotes answering me were always distant, and when we would see deer or elk in the daytime, they never bothered or got any reaction from any of the horses. We went home, and I kept insisting to George that what answered me was no dog....I have been around dogs all my life. (I know dogs, he does not.) It didn't sound like a dog or wolf howl as it was much deeper, and of course had much more volume than any dog or other canine would be capable of. It was a year or so ago that I came across some bigfoot sites, and I played some of the recorded .wav files. I got chills when I heard the one howl recorded in Columbiana County, Ohio, as it was almost exactly what I heard that night that winter, but what I heard was much much closer to me. I also noted that in this county, just a few months after this experience, a woman heard a bigfoot in the Teanaway area, which would be just north of where my horses were kept. I believe what I heard was a bigfoot. I should point out that I did not feel threatened in any way when this happened..it scared me due to the (guesstimated) size of the creature that howled back at me, and the fact that I did not know what it was, but I didn't feel the need to turn and run for safety. Had I an inkling that it was indeed a lost or stray dog, or that it belonged to someone in the area, I would never have simply left it there. I would have gone to try to coax it to me, or followed up on finding dogtracks, etc. and gotten the dog some help. (Not only for the dog's sake, but stray dogs can harass or harm horses, and I wouldn't leave any dog to cause problems for my horses. Horses must conserve every bit of energy they have, esp. in such a harsh winter as that one. I HAVE contacted people about any dog that has harassed my horses, as I had to do prior to that winter when my horses were harassed by a border collie mix. I didn't want to have to have the dog shot.) Had I thought it was a wolf, I would also have done something to protect my horses.