Mount Lassen NP

12. Looking Across to Chaos Crags

Chaos Crags is the youngest group of lava domes in Lassen Volcanic National Park, California, having been formed as five dacite domes 1,100-1,000 years ago. The cluster of domes are located north of Lassen Peak. From the base of the crags and extending toward the northwest corner of the park is Chaos Jumbles, a cold rock avalanche which undermined Chaos Crags' northwest slope 300 years ago. Riding on a cushion of compressed air, the rock debris traveled at about 100 miles per hour (160 km/h), flattened the forest before it, and dammed Manzanita Creek, forming Manzanita Lake. n 1974 the United States Park Service took the advice of the USGS and closed the visitor center and accommodations at Manzanita Lake. The Survey stated that these buildings would be in the way of a rockslide from Chaos Crags if an earthquake or volcanic eruption occurred in the area.