The Chaos Crags, a series of five small lava domes, represent the youngest part of Lassen volcanic center's dome field, reaching an elevation of about above their surroundings. They were produced by vigorous explosive eruptions of pumice and ash followed by effusive activity, which created unstable edifices that partially collapsed and formed pyroclastic flows made of incandescent lava blocks and lithic ash. Six domes were originally formed, though one was destroyed by a pyroclastic flow. Roughly 350 years ago, one of the domes collapsed to produce the Chaos Jumbles, an area where three enormous rockfalls transformed the local area and traveled as far as down the dome's slopes.