"This natural feature is created when a surge of water flows down from a steep landscape to a flatter one, carrying with it sand, pebbles, small rocks, and even boulders...aluuvium, or debris, that is carried by water. When the water reaches a flatter landscape, it loses speed and energy needed to continue carrying the alluvium. As a result, the water begins to spread out and creates a fan shaped area of deposition." (from a posted information sign) This is a downstream view of the current flow and part of the alluvium.
