Source Lake Falls is a waterfall on South Fork Snoqualmie River in King County, Washington, in the North Cascades region, with a total height of about 120 feet. It lies about 14.1 miles east of Tanner and roughly 32.3 miles southeast of Sammamish as the crow flies.
At 120 feet it is taller than the typical Washington waterfall of about 82 feet, ranking 346th of 941 with a recorded height. The tallest single drop is 60 feet. The water comes down as a tiered waterfall, falling in several distinct steps one after another, combined with a horsetail character. It falls in 3 drops.
The North Cascades are a wilderness of jagged peaks, glaciers and deep, forested valleys of western hemlock, silver fir and Douglas fir, with some of the heaviest snowfall in the country. Meltwater from glaciers and snowfields pours down thousands of feet of cliffs in countless cascades and horsetail falls. South Fork Snoqualmie River carries 7 recorded waterfalls; the biggest of them reaches 230 feet.
There are 236 recorded waterfalls in King County. Alpental Falls, a 250-foot horsetail waterfall, is about 1.1 miles away. Rock Creek Falls, a 1,180-foot tiered horsetail waterfall, is about 1.2 miles away. Melakwa Falls, is about 1.3 miles away.
Source Lake Falls is located at 47.4549° N, 121.4460° 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.