Untitled Sighting

I went out to custer state park after the buffalo roundup to just rest and ride my horse....I rode all day friday. I came back to camp ,fed and watered my horse, I was the only one in camp. I went to town to eat as I was tired and did not feel like cooking. I went to Custer, had a burger and left for camp. As you pass BLUE BELL loge you take a dirt road about 3 miles to camp, at the 2.5 sign you go up a good size hill, just as I came to the top of the hill, to my left I saw something coming down the hill. It hit the road and took one long step and was down the hill on my right. There was a lot of dust and rocks that came down with it, but I saw it very good. It was 6 to 7 ft tall, it had brown and red hair all over, looked like a gorilla only more manlike. It was not a buffalo or a deer or elk or bear. I went back to camp fast, put the horse in the trailer and went home. I did not say anything to anyone, as they think I am nuts anyway. I know what I saw was not a man in a suit .