Rosario Falls is one of the recorded waterfalls in San Juan County, Washington, in the Puget Lowland region. It lies about 10.5 miles northeast of Friday Harbor and roughly 18.9 miles southwest of Bellingham as the crow flies.
No height measurement has been recorded for it yet.
The Puget Lowland is a glacially shaped basin of low hills, lakes and wetlands between the Olympics and the Cascades, once covered by Douglas fir and western red cedar and now the most settled part of Washington. Streams here run through terraces of glacial till and outwash, with waterfalls where creeks cut through the deposits.
There are 9 recorded waterfalls in San Juan County. Cascade Falls, a 40-foot veiling horsetail waterfall, is about 1.6 miles away. Rustic Falls, a 10-foot veiling plunge waterfall, is about 1.6 miles away. Cavern Falls, a 20-foot tiered horsetail waterfall, is about 1.7 miles away.
Rosario Falls is located at 48.6488° N, 122.8667° 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 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.