But a spokeswoman for the Washington Marine Debris Task Force, Virginia Painter, says an official determination is unlikely because there are no markings.
The cylinder looks like a 19-foot-long pipe, 3 feet in diameter with end caps.
A ranger found it Tuesday on Long Beach at Cape Disappointment State Park. Painter says it will be removed.
The state Fish and Wildlife Department is checking for any invasive species in the seaweed clinging to the cylinder.
A 66-foot dock found Dec. 18 on a remote beach near Forks was determined to be tsunami debris from Japan.