Olallie State Park is a public recreation area featuring multiple waterfalls located five miles (8.0 km) southeast of North Bend, Washington.

[2] The state park spans a 3.5-mile (5.6 km) stretch along the South Fork of the Snoqualmie River.

Twin Falls features a well-hidden underground run-of-the-river hydroelectric project that generates 24 MW of electricity.

Park activities include fishing, hiking, mountain biking, bird watching, and rock climbing.

[2] Completed in 2017, the Ollalie Trail added 9.2 miles (14.8 km) of backcountry mountain biking.