Screaming or howling in Pacific County, Washington

My son and I were elk hunting when we came across what we think was a Sasquatch. We were about two miles from the main river and up in what we call "Iman Valley". Its up the lower fork of the North River, sometimes called "Smith Slough". Its a big alder bottom with a ridge coming up right in the middle of it. We had just climbed a ridge, got to the top, took a break, and started down the top of a ridge and I was about 30yds in front of my son when I thought that I heard something. The area was pretty clear with hardly any underbrush. I turned around and looked at my boy and he shook his head that he heard it also. I was in a wide spot on the ridge while my boy was standing on a narrow part of it. I started to sneak over to where I could see down the side of the ridge when I heard a snap. I took off to where I could see and thats when I saw whatever it was standing in a pile of old shake bolt cuttings. It jumped and sort of took hold of a tree and swung around behind it. All I got to see was from the shoulders down. It was a real pretty brown, long hair, and from what I could tell was over six feet tall, but not real gigantic. I kept the tree between us and itself and took off down the ridge. My son saw about the same thing that I did, but he said that he heard a high pitched scream and some grunting. I'm getting so I can't hear high pitched sounds, so I didn't hear it. We went down to where we last saw it but couldn't find any sign of what it might be. Normally there is lots of elk and deer sign in the area, but this year there was absolutly no sign. It was as if everything moved out of the area... When we got home I called the "Bigfoot" Society (1-800-bigfoot) and talked with some people there. Three guys, can't remember all of their names, but one of them was Peter Byrne from Oregon, and it seems the other two were from Paulsbo, WA. They came to my place in Westport, WA, and I took them up to where we had seen it. They seached for quite a while and said that they found tracks but weren't sure about them being human or not. I told them that we hadn't been in the area of the tracks, but that other hunters hunted the ridge and it might be their tracks. They figured from our story that for sure we saw a "bigfoot". I remember them saying that they sure wished they could have seen what we saw up there. I've hunted all of my life (I'm 64), and know that whatever it was, it wasn't a deer, elk, bear, or anything else I ever seen before. I had a float house on the North River and hunted this area for about 40 years and other than one other year of seeing no sign, we always had good luck on the deer and elk. I haven't been back up there for about three years now as most of it has been logged, and I also sold the Float House.