For the past ten thousand or more years, the bedrock at the top of the mountain's escarpment has been weathered and eroded by ice, running water and wind. Once rocks were loosened, gravity and small landslides transported them down to the base of the mountain. When enough of them had accumulated, a talus slope formed. Talus slopes are very common along the walls of glaciated valleys across Canada, northern Europe and Asia. The talus, or loose rocks, in this picture varies greatly in size.
Some rocks are simply hand-sized boulders.
Some are the size of a small car. Others are as big as a single-story house. But, even at this size, the rocks are far from being stationary. Continued erosion and the pull of gravity keep the rocks creeping down-slope. Most of the time the pace of the creep would make a snail seem like a speedster.