Olallie State Park

Olallie State Park is a natural preserve along the South Fork of the Snoqualmie River with old-growth forests, several waterfalls, and numerous hiking trails. The area also features six climbing zones with varying difficulty levels and opportunities for mountain biking and fishing.

The area was established in 1950 when Washington State Parks acquired 160 acres from Puget Sound Power and Light. It was originally known as Twin Falls State Park before receiving its current name.

The name Olallie comes from the Chinook language and refers to the berries that grow abundantly here. You can spot these wild berries along the trails during warmer months.

The park is open year-round, though winter conditions can be slippery and good footwear is advised. The best time to visit is late spring through early fall, when trails are dry and waterfalls flow with plenty of water.

Beneath the park lies a hidden hydroelectric facility operating roughly 100 meters underground that generates power for the region. This underground system remains invisible to visitors but works continuously beneath the trails and waterfalls.

Location: Washington

Location: King County

Operator: Washington State Parks and Recreation Commission

Website: https://parks.wa.gov/555/Olallie

GPS coordinates: 47.43722,-121.65306

Latest update: December 11, 2025 18:06