Screaming or howling in Trinity County, California

I was working in the northern part of New Mexico training to be a Wildland Fire Fighter. In September 2003 (maybe the second week of that month) I was dispatched with 22 other people to the Del Loma Fire in the Shasta/Trinity Forest area, the Northern part of California. Each Crew had about 20 people, our plane that left Albuquerque held 2 crews. For almost the whole two weeks, we were all on standby. On the 4th to the last day of our 2 weeks of Fire call, we were setting up camp close to a river, about 5-10 miles out from the original forest fire. It was close to sun down when, a couple of guys were amazed at something. I heard them from inside my tent, but just ignored the whole thing until one of my crew members came and pulled me out of my tent. I had no idea what I was supposed to be looking at or for. He pointed across the river and I was in shock when he pointed out the biggest, hairiest mammal I had ever seen just walking along the river side minding his own business. It stopped and looked at us. The way he stood on his hind legs was like an ordinary human. He had dark, long hair and stood about 7ft tall with a muscular build. At this point I was the 4th person standing there in amazement. Maybe about 5 minutes of watching him watch us, with more people coming out with flashlights (because the sun was still going down) he darted in to the trees. He was running, taking long strides, and was gone in about 3 seconds.....and was literally pushing trees out of his way (not breaking them, but pushing them out of his way). The trees behind him on his path up the mountain were swaying back and forth. I was surprised to see to these trees moving because they are thick in width and very tall. By this time it was dark but lit enough to see which way he was headed. Up the mountain a little, there was a clearing, where we spotted him again before he disappeared for good. He made no noise, no yelling or screaming. He was just as timid as can be. I have heard many stories about Bigfoot, and known that they are real but when seeing one in real life....you get a sense of respect for them and just have that feeling that there is more to life than you know.