Historic Resource Study, Crater Lake National Park, Oregon, 1984
V. Geological and Biological Information on Crater Lake Area
E. Points of Geological Interest in Crater Lake National Park
13. Castle Rock (Pumice Castle)
Below Cloudcap a bright orange and pink formation of pumice and tuff protrudes from the caldera wall composed of layers of pumice laid down in the early days of Mazama and covered by later eruptions. Hot gases have colored them orange and apricot. Exposed during Mazama’s final collapse, they have since been eroded by wind and water into a formation called Castle Rock.