Rainbow Falls State Park

Rainbow Falls State Park
Falls on the Chehalis River
Location in the state of Washington
Rainbow Falls State Park (the United States)
LocationLewis County, Washington, United States
Coordinates46°37′43″N 123°13′52″W / 46.62861°N 123.23111°W / 46.62861; -123.23111
Area129 acres (52 ha)
Elevation331 ft (101 m)
Established1935
OperatorWashington State Parks and Recreation Commission
WebsiteRainbow Falls State Park

Rainbow Falls State Park is a public recreation area on the Chehalis River. It is situated off State Route 6 and is approximately 1.0-mile (1.6 km) east of Dryad, Washington.

The state park's 129 acres (52 ha) rests on grounds originally part of an inland sea. Geological features include 3,900 feet (1,200 m) of shoreline of basalt rock formed 17 million years ago and the waterfall for which the park is named. Surviving old-growth trees, some of the last standing in the Chehalis Valley, occupy the site.

The park was built by the Civilian Conservation Corps, completed in 1935. Flooding of the Chehalis River has led to several damages at the park, including the loss of some waterfall features and a popular footbridge after the Great Coastal Gale of 2007.

Amenities include campgrounds, miles of trails, and can be accessed by a short spur route of the Willapa Hills Trail. Rainbow Falls State Park is the end point of the annual Pe Ell River Run that began in 1978.