33 C.F.R. § 110.128

The waters of the Columbia River between Sand Island and Government Island, bounded on the west by pile dike U.S. 5.75 and a line extending true north from the northerly end of the dike to the south shore of Sand Island and bounded on the east by a line bearing 339°15′ true, from a point on Government Island at latitude 45°35′10″, longitude 122°32′41″, to the southerly shore of Sand Island.