Invasion

Invasion Description

1st Record: Kalama/WA/Columbia River (1933, Chapman 1942; Lampman 1946)

Geographic Extent

Kalama/WA/Columbia River (1933, Chapman 1942; Lampman 1946); Portland/OR/Willamette River-Columbia River (Lampman 1946; Hughes and Gammon 1987; Farr and Ward 1992); North of Knappa/OR/Grizzly Slough (2001, USGS Nonindigenous Aquatic Species Program 2014); north of hwy 30, near Westport, 10 miles west of Clatskanie/OR/Westport Slough (2001, USGS Nonindigenous Aquatic Species Program 2014);