Chaos Crags Southern end of the Chaos Crags vent complex. A compound ejecta ring marks the vent crater for early pyroclastic phases of the Chaos Crags eruptive sequence. A group of volcanic domes extruded in a cluster to the north of these partly preserved craters, forming the rough surface on the skyline. Both the pyroclastic and the lava eruptions occurred within a short period of time about 1,100 years ago. Photo by R. L. Christiansen, September, 1985.