The Puyallup River begins in two forks, the North Puyallup River and the South Puyallup River. Both originate at glaciers on Mount Rainier. The North Puyallup River flows from the toe of Puyallup Glacier, while the South Puyallup River flows from Tahoma Glacier. The two streams flow through the western part of Mount Rainier National Park, joining just outside the park boundary and forming the Puyallup River proper.