Sunken Arch Falls is a waterfall on Stevens Creek in Lewis County, Washington, in the Cascades region, with a total height of about 29 feet. It lies about 30.8 miles east of Eatonville and roughly 40.2 miles southeast of South Hill as the crow flies.
At 29 feet it is on the modest side for Washington, where the typical waterfall with a recorded height stands around 82 feet; it ranks 793rd of 941. The water comes down as a segmented waterfall, splitting into two or more separate streams as it falls, combined with a plunge character.
The Cascades are a high volcanic range of snow-capped peaks, deep glacial valleys and dense conifer forest of Douglas fir, western hemlock and true firs, with abundant rain and snow on the western slopes. Basalt cliffs and lava flows give the region one of the highest concentrations of waterfalls in the country. Stevens Creek carries 6 recorded waterfalls; the biggest of them reaches 375 feet.
There are 180 recorded waterfalls in Lewis County. Lower Stevens Creek Falls, a 34-foot slide punchbowl waterfall, is under a mile away. Middle Stevens Creek Falls, a 15-foot plunge punchbowl waterfall, is under a mile away. Cougar Falls, a 102-foot plunge waterfall, is under a mile away.
Sunken Arch Falls is located at 46.7514° N, 121.6383° W. The listing is based on the World Waterfall Database, one of the sources compiled by the U.S. Geological Survey in its inventory of waterfalls and rapids of the conterminous United States. The creek name is confirmed against the federal Geographic Names Information System. The exact position has not yet been verified on aerial imagery, so treat the map pin as approximate. Details on trails, parking and access have not been documented for this waterfall yet.