Lahars from the Cascade Volcanoes are historically common. Orting is situated in the floodplain of the Puyallup River and on top of the debris field of past lahars from Mount Rainier, including the Osceola Mudflow. The Osceola Mudflow followed an eruption 5,600 years ago that left a horseshoe-shaped crater in Mount Rainier comparable to that of the 1980 eruption of Mount Saint Helens and deposited debris across a area as far as Commencement Bay on Puget Sound. Another event, the Electron Mudflow, produced a lahar that was deep when it reached the Puget Sound lowland.