Borderline Falls is a 20-foot waterfall on West Fork Miller River in King County, Washington, in the North Cascades region. It lies about 19 miles southeast of Gold Bar and roughly 31.1 miles east of Sammamish as the crow flies.
At 20 feet it is on the modest side for Washington, where the typical waterfall with a recorded height stands around 82 feet; it ranks 851st of 941. By form it is a tiered waterfall, falling in several distinct steps one after another, combined with a cascade character. It falls in 2 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. West Fork Miller River carries 3 recorded waterfalls, and Borderline Falls is the tallest of them.
King County holds 236 recorded waterfalls, and several are close by. Immigration Falls, a 20-foot horsetail waterfall, is under a mile away. Francis Falls, is about 1.2 miles away. Mohawk Falls, a 349-foot tiered horsetail waterfall, is about 1.3 miles away.
Borderline Falls is located at 47.6591° N, 121.4122° 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.