The subterranean Echo River emerges at Echo River Spring a short walk away from the Green River Ferry. The barren banks around the spring reflect the changing volume of water that can flow from the spring and/or backfill from the Green River during flood. The spring water has a bluish gray color from the high volume of dissolve minerals in the water, and a low cloud of fog hangs over the cool spring water on a hot summer day when this picture was taken. Limestone outcrops around the spring are part of St. Louis Limestone.