A rapids is a “skookumchuck” in the Chinook language, literally meaning strong water. In coastal usage this refers to the powerful tidal rapids at the mouths of many coastal inlets in the Pacific Northwest where the tidal range can exceed 20 ft (6 m). Brownson Island is located on the west side of Ernest Sound in the Alexander Archipelago of Southeast Alaska. The island is separated from Etolin Island by the narrow Canoe Passage, which is navigable only for small boats, and was first described by Lieutenant Commander A. S. Snow of the U.S. Navy in 1886. Click here to download the CoastView app and explore the skookumchucks of Brownson Island.