An account in Lewis And Clark County, Montana

I was 11 or 12 at the time. I was at a boyscout Jamboree. My friend came to me and asked if I beleived in bigfoot. He then told me to follow him because he saw a bigfoot. We walked about a half mile to the rivers edge. Accross the river we watched what looked like a large gorilla like creature about 6 ft tall standing next to the river picking leaves off a bush and eating them. We watched for a couple minutes until it walked into the brush and disappeared. It was not a bear. It picked the leaves off the tree just as a human would. We stayed in the area as much as possible the next few days but never saw it again.