As we continue up the mountain it's easier to climb on the big rocks. The grassy areas are covered with small rocks which move too easily underfoot. Climbing on the grass causes plant damage and erosion; another reason to stick to the rocks. Eventually as we get higher, there is no grass; only rocks or snowfields. Here, Ron B. uses his arms to steady himself as he moves slowly through a boulder field. We're not moving very fast at 13,000 feet. The air is thin and we have to breathe at least twice with every step.