All of that portion of Ollala Slough in Lincoln County, Oregon, above a point where a line that is one hundred and twenty rods south and running east and west and parallel with the section line between sections 8 and 17 in township 11 south, range 10 west of the Willamette meridian, crosses said stream, is declared to be a nonnavigable stream.
33 U.S.C. § 39