Rambling down 77 feet of granite, the South Fork of the Snoqualmie River creates Weeks Falls on the eastern end of 2,500-acre Olallie State Park and on the opposite side of the park from Twin Falls.
From the day use parking lot, follow the river upstream for 0.4 miles along a relatively broad trail passing by thimbleberry, lady fern, old-growth western redcedar, and a relatively out-of-place giant Sitka spruce (which tend to grow more dominantly closer to the Pacific Ocean) to quickly reach Weeks Falls. En route you'll also pass the discharge point of Weeks Falls Hydroeletric Plant, a maximum 5-megawatt powerstation, which at its capacity has the ability to power roughly 800 homes in Kings County.
Note: Swimming below the falls adjacent to the hydroelectric plant is not permitted. You'll enjoy swimming and relaxing on the riverbanks near the main parking lot at Snoqualmie River Picnic Area.