The park's name, Olallie, is derived from the Chinook Jargon word for 'berry'.
Twin Falls drops 135 feet across three tiers into a deep, forested gorge.
Weeks Falls features a hydroelectric plant that remains largely hidden from trail viewers.
The park provides critical habitat for Roosevelt elk and black bears.
The South Fork Snoqualmie River, which runs through the park, is a popular drainage for snowmelt from the nearby peaks.
Much of the forest in the park is secondary growth, though pockets of old-growth timber remain in protected ravines.
Olallie State Park is a 2,367-acre protected area located in the Cascade Mountains along the South Fork Snoqualmie River. The park is defined by the Twin Falls and Weeks Falls, both accessible via distinct trail systems. Twin Falls Trail provides a moderate 2.6-mile round-trip hike leading to observation platforms overlooking the multi-tiered waterfall. Weeks Falls is reachable via a short, accessible interpretive loop. The park serves as a hub for regional recreation, connecting to the larger Palouse to Cascades State Park Trail. Its old-growth forest habitat features a dense canopy of Douglas fir, western hemlock, and western red cedar. The terrain is characterized by steep river canyons and rugged mountainous topography. The park is managed by the Washington State Parks and Recreation Commission.
The wooden observation bridge at the Twin Falls overlook offers the clearest view of the upper and middle tiers.
Wear waterproof footwear, as the trails near the waterfalls are frequently muddy and damp.
Check the Washington State Parks website for Discover Pass requirements before arriving.
Visit on weekdays to avoid significant crowds at the Twin Falls trailhead parking lot.
Do not attempt to scramble down the steep, unmarked slopes to the riverbanks, as these areas are unstable and dangerous.
The park is open year-round, though upper parking areas may be inaccessible during heavy winter snowfall.
Stay on marked trails to protect sensitive riparian vegetation; leash your dog at all times.
