Screaming or howling in Tuolumne County, California

We were camping in tents with our horses tied on a rope between the trees. In the middle of the night I was awakened by a terrifying scream kind of like a woman screaming and then I heard what sounded like my horses were loose and running up the hill. I ran out of my tent to where the horses were and shined my flashlight. All my horses were tyed up and staring up at the top of the hill very upset. We didn't hear or see anything else so we went to bed. The next morning there were footprints going up the hill like whatever it was had two large feet with a big toe. The next evening at dust we tyed our horses up in the meadow. Our camp was about 300 yards away when we heard a loud sound like the horses startled something, we looked up to see some huge thing running extremely fast across the meadow away from the horses in a cloud of dust. We ran over there and one horse was so scared it had jumped over another horse while they were tied up. So we tyed the horses up in the orginal spot and never heard another thing on the trip. We stayed a week and we felt very stange like something was watching us. There were no animals in the area no birds, squirrels etc etc. We were in the middle of nowhere and we would hike around our camp and there would be stacked rocks little bunches all around the area and the next day they would gone. This went on through out the week and one day we smelt this odor that was so bad around our tent when we came back from a ride but we never saw anything else. This went on for two years that we returned to the exact camping spot. Then one year we were camping and we didn't feel that same strange feeling we had that someone was watching us, there were birds squirrels insects all kinds of signs of life. That last day a bear came into our campsite and the horses didn't seem to care. So we were convinced that it could"nt have been a bear the first couple of encounters. Not with the sound it made and the way it ran.