Mount Rainier Reflected in Tipsoo Lake

Description: The early lavas formed a "proto-Rainier" or an ancestral cone prior to the present-day cone. The present cone is over 500,000 years old. The volcano is highly eroded, with glaciers on its slopes, and appears to be made mostly of andesite. Rainier likely once stood even higher than today at about 16,000 feet (4,900 m) before a major debris... ( +expand to view full text )

Description: The early lavas formed a "proto-Rainier" or an ancestral cone prior to the present-day cone. The present cone is over 500,000 years old. The volcano is highly eroded, with glaciers on its slopes, and appears to be made mostly of andesite. Rainier likely once stood even higher than today at about 16,000 feet (4,900 m) before a major debris avalanche and the resulting Osceola Mudflow 5,000 years ago.