Twin Falls is a 230-foot tiered horsetail waterfall on the South Fork Snoqualmie River in Olallie State Park, King County, Washington. The river drops through a forested gorge in a series of tiers, and a short, well-built trail with stairs and a bridge makes it a family hike from the Interstate 90 corridor.
The falls
In-person surveys count five drops. The bottom tier is the largest at 110 feet, and the footbridge crossing the gorge looks down on the upper cascades rather than on every tier equally. Earlier surveys listed six drops with a 135-foot tallest drop. Water is diverted upstream for hydropower, so flow is regulated and drops sharply in late summer.
Getting there
The trailhead is at the end of SE 159th Street, reached from I-90 exit 34 via 468th Avenue SE, and has a restroom. The hike spans 2.4 miles round trip with 500 feet of gain, rated easy to moderate. The park is day-use only, open from 6:30 a.m. to dusk year-round, and parking requires a Discover Pass ($10 a day or $45 a year).
Since March 16, 2026, Washington State Parks has closed the Lower Falls Viewpoint because of storm damage to the structure; the closure was still posted in late September 2026. Check the park's alerts before going.
When to go
Visits are best in winter and spring, when the river runs high. Late-summer flow is much lower because of the diversion, and low-elevation snow occasionally reaches the trail in winter.
On site
The trail climbs stairs and short, steep slopes, and the lower viewpoint normally sits at the bottom of 104 steps, now closed. Dogs are allowed on leash. Kayaking is permitted only downstream of the falls. In October 2024 Snoqualmie firefighters responded to a hiker who had fainted about three-quarters of a mile up the lower trail.
History and name
The falls were historically called Upper Snoqualmie Falls, and the upper sections are sometimes called Middle and Upper Twin Falls. The state bought the land from Puget Sound Power and Light on October 25, 1950, and it was first named Twin Falls State Park before becoming part of Olallie.
Nearby
Iron Horse Falls is about 0.9 mile away, Boxley Creek Falls is about 1.5 miles away, and Change Creek Falls is about 1.6 miles away. Weeks Falls, 2.5 miles away, is on the same river. The nearest town is Riverbend, 2.9 miles away.
Distances are straight-line.