Report 5104: Hunters are intimidated out of their hunting ground near Bear Valley

My experience takes place around the end of October close to the end of deer season in Alpine County, California about 1982-83. Myself and 3 other hunters were getting a last deer hunt in Pacific Valley. We have hunted there many times over the years, however this time we were the only ones left in the valley. Myself and a friend of mine were hunting together near the Bull run trail head about 5 miles from camp. That day seemed odd after we got up the hill because we could hear no sounds and we could not see anything moving.(We both have biology backgrounds) We were on the edge of a meadow and had somthing like a rock fly over our heads. Be both heard it and I hit the ground. We could not see anyone and the hair started raising on the back of our necks. After checking the area we decided to go down the hill back to camp. The whole way down the trail somthing paralleled us just out of sight. Every few hundred feet it would roll or throw a huge rock down the hill along side the trail. I dropped to a knee a couple of times and swung my rifle towards the area where the boulers were rolling and could not see anything in my scope. We were getting a little shook up at this point and could not figure out what was following us and rolling the rocks. We have never seen any bears while hunting there and ruled out the possibility of a bear trying to scare us by throwing rocks. This continued until we got to the dirt road that took us back to camp. I would say this went on for about 20 minutes or about one mile. Once we were back in camp we related the experince to the other two hunters. The rest of the afternoon we noticed that no animals were around. We always have had animals around camp, chipmonks, birds,and the occasional pine martin. After dinner we sat around the camp fire and were getting our gear ready for the next day almost bed time when across the creek out of our lantern light a large tree went down. It was a huge crash. It could have been a natural occurence, but with the earlier events we decided that somthing did not want us in that valley. We decided that no one was going to get any sleep that night anyway so we packed up and left for home. I have only been back there one time after that and saw through the tent screen somthing pick up my red ice chest with a white lid. I yelled at it and it put the ice chest down and ran off. I could not see what it was. My partner dismissed it as a deer going throuh camp and went back to sleep. I never heard anything else the rest of our trip.