Two hunters experience prolonged tree shaking and rock throwing near Nordegg witnessed in Alberta, Canada

Open Map

We were out bow hunting in the Black Stone Gap area north west of Nordegg, Alberta and had something happen I can't really explain. We set up camp about 9:30 Friday night Sept 9, 2016 and started a fire to cook dinner. We hear noises coming from the tree line about 25 yards away and got out the shot guns figuring it might be a bear. After about a 1/2 hour of hearing something moving in the bush, my buddy fired a round into the air to try to scare it off. Not 20 seconds later a rock the size of a soccer ball came flying out of the bush and landed beside us and a tree started to shake violently back and forth and another rock came out of the bush at us. This went on for a good 20 minutes with 17 rocks being thrown. We packed up camp and left. I've hunted all my life and I know bears can shake trees but they cant throw rocks 25 yards. I don't know if I should report this here or not but I'm trying to figure out what the hell happened that night it scared two experienced hunters and made m...