The Hoh Rainforest is located on the Olympic Peninsula in western Washington state, USA. It is one of the largest temperate rainforests in the U.S. Within Olympic National Park, the forest is protected from commercial exploitation. This includes 24 miles (39 km) of low elevation forest 394 to 2,493 feet (120 to 760 m) along the Hoh River. The Hoh River valley was formed thousands of years ago by glaciers.