The U.S. Army Corps of Engineers, in a statement from their office in Portland, Oregon, is advising recreational boaters and commercial mariners that recent high water levels may be concealing some pile dikes on the Columbia River.

Pile dikes are frequently just below the surface during high water events and can cause serious damage to vessels attempting to transit over them.

U.S. Army Corps of Engineers photo

Pile dikes are also called wing-dams and they are wooden structures that extend from the shore to the managing the flow of the navigation channel. Information and photos of pile dikes can be found here.

Getty Images Oxford Punting

Commercial and recreational mariners should review the Corps' channel conditions maps regularly for the locations of pile dikes and other obstacles here.