Boaters spending their Memorial Day weekend at Lake Powell caught this footage of a large rock slide.
Joe Cook, a research geologist with the Arizona Geological Survey, said the kind of rockfall is called a “rock topple,” and the critically low water levels were likely a contribution.
“The saturation and then drying with the falling water levels kind of contributed to that thing falling over. It might have fallen over anyway but having a reservoir there may have sped up the process,” Cook said.
No one was injured.