The Ohanapecosh River originates from meltwaters of the lower part of Ohanapecosh Glacier on the southeastern slopes of Mount Rainier. It flows southeast through Indian Bar, a broad, flat area of rocky debris. At approximately Ohanapecosh river mile 15 the Ohanapecosh plunges over Wauhaukaupauken Falls. The Wonderland Trail crosses the river near the falls. North of the river there is an alpine cirque known as Ohanapecosh Park. A similar cirque to the south is called Cowlitz Park. Below Wauhaukaupauken Falls the Ohanapecosh then flows more generally east over more waterfalls. The tributary Boulder Creek joins from the north.