| Olallie State Park | |
| Map: | USA Washington#USA |
| Map Size: | 280 |
| Relief: | 1 |
| Location: | King, Washington, United States |
| Coordinates: | 47.4461°N -121.7039°W |
| Area Acre: | 2329 |
| Elevation: | 623feet |
| Established: | 1950 |
| Operator: | Washington State Parks and Recreation Commission |
| Website: | Olallie State Park |
Olallie State Park is a public recreation area featuring multiple waterfalls located 5miles southeast of North Bend, Washington. The state park spans a 3.5miles stretch along the South Fork of the Snoqualmie River. The most prominent feature of the park is 135adj=midNaNadj=mid Twin Falls.
The park originated in 1950, when Washington State Parks purchased a 160-acre parcel from Puget Sound Power and Light. Originally named Twin Falls State Park, following the park's expansion in 1976 its name was changed to Olallie, after a Chinook word for the berries which are common in the park.
The park features old-growth forests and five notable waterfalls: Twin Falls, Middle Twin Falls, Upper Twin Falls, Weeks Falls, and Upper Weeks Falls.
Twin Falls features a well-hidden underground run-of-the-river hydroelectric project that generates 24 MW of electricity.[1] The powerhouse is located 325feet below ground.
Park activities include fishing, hiking, mountain biking, bird watching, and rock climbing. Completed in 2017, the Ollalie Trail added of backcountry mountain biking.